these multi-port instruments are generally robotically controlled and provide end effectors ( tips ) that are similar to those used in either open or laparoscopic surgery . we offer advanced instrumentation for the da vinci xi and da vinci x platforms , including da vinci energy and da vinci stapler products , to provide surgeons with sophisticated , computer-aided tools to precisely and efficiently interact with tissue . da vinci x and da vinci xi surgical systems share the same instruments whereas the da vinci si surgical system uses instruments that are not compatible with da vinci x or da vinci xi systems . we currently offer nine core instruments on our da vinci sp surgical system . we plan to expand the sp instrument offering over time . training technologies include our intuitive simulation products , our intuitive telepresence remote case observation and telementoring tools , and our dual console for use in surgeon proctoring and collaborative surgery . during the first quarter of 2019 , the fda cleared our ion endoluminal system to enable minimally invasive biopsies in the lung . our ion system extends our commercial offering beyond surgery into diagnostic procedures with this first application . we are introducing the ion system in the u.s. in a measured fashion while we optimize training pathways and our supply chain and collect additional clinical data . we are early in the launch and have placed 36 ion systems for commercial use as of december 31 , 2020. ion systems are not included in our da vinci surgical system installed base . we currently have 3 ion systems placed with hospitals for gathering clinical data in addition to the systems placed for commercial use . the success of new product introductions depends on a number of factors including , but not limited to , pricing , competition , market and consumer acceptance , the effective forecasting and management of product demand , inventory levels , the management of manufacturing and supply costs , and the risk that new products may have quality or other defects in the early stages of introduction . 52 table of contents covid-19 pandemic procedures prior to the spread of covid-19 in the first quarter of 2020 , we experienced procedure growth trends consistent with those experienced in the fourth quarter of 2019 , including strength in general surgery , growth in mature procedures in the u.s. , and growth in ous urology . beginning in january 2020 , we saw a substantial reduction in da vinci procedures in china and , by early february 2020 , procedures per week in china had declined by approximately 90 % compared to the weekly procedure rates experienced in early january 2020. as the covid-19 pandemic subsided in china in march 2020 , da vinci procedure volume began to recover and , by the end of the first quarter of 2020 , china procedures per week were approximately 70 % of the early january 2020 weekly procedure rate . as the covid-19 pandemic spread to western europe and the u.s. , we experienced a significant decline in da vinci procedures in the last half of march 2020 , and procedures per week in the u.s. declined to approximately 65 % of the weekly procedure rate experienced earlier in the first quarter of 2020. in april 2020 , procedures per week in the u.s. continued to decline , reaching approximately 30 % of pre-covid-19 levels . in may and june , u.s. procedures began a recovery phase , as covid-19 cases dropped and elective procedures were permitted , and , by the middle of june , had grown to nearly the same level as that measured in the first two weeks of the first quarter of 2020. however , in the last two weeks of june and into july , with the resurgence of covid-19 cases , some regions postponed elective procedures , and we experienced a corresponding decline in da vinci procedures . the impact of covid-19 in europe during the second quarter varied by country with procedures in italy , france , and the uk declining more steeply , while germany experienced a year-over-year increase in procedures . during the second quarter of 2020 , china procedures per week continued to increase to a level consistent with the early january 2020 weekly procedure rate . in the third quarter of 2020 , procedures recovered slowly in the u.s. , leveling off near pre-covid-19 levels towards the end of the quarter . outside of the u.s. , da vinci procedures varied in the third quarter of 2020 , depending on the spread and or resurgence of covid-19 . for example , covid-19 had a less significant impact in germany where da vinci procedures grew at mid-single digits relative to the third quarter of 2019 , while it had a more significant impact in the u.k. where da vinci procedures declined year over year . procedures in china grew significantly year over year in the third quarter of 2020 , while regional covid-19 outbreaks resulted in year-over-year procedure growth rates in japan slowing somewhat relative to earlier in the year . the covid-19 pandemic has also affected the volumes of certain procedure types differently . for example , patient concerns over exposure to covid-19 and the fact that prostate cancer can be slow growing , combined with lower prostate diagnoses and treatments , have caused the number of dvp procedures to decline in the third quarter of 2020 relative to the third quarter of 2019. da vinci bariatric procedures grew significantly year over year in the third quarter of 2020 due to our optimized instrument set and focus by our sales organization and may also have benefited from certain patients prioritizing weight loss as obesity is a significant covid-19 risk factor . story_separator_special_tag as of december 31 , 2020 , a total of 901 da vinci surgical systems were installed at customers under operating lease or usage-based arrangements . our system leasing and usage-based models provide customers with flexibility regarding how they acquire or obtain access to our systems . we believe that these alternative financing structures have been effective and well-received , and we are willing to expand the proportion of these structures based on customer demand . as revenue for operating leases and usage-based systems is recognized over time , total systems revenue growth is reduced in a period when the number of operating lease and usage-based placements increases as a proportion of total system placements . our exposure to the credit risks relating to our lease financing arrangements may increase if our customers are adversely affected by changes in healthcare laws , coverage and reimbursement , economic pressures or uncertainty , or other customer-specific factors . in addition , as customers divert significant resources to the treatment of or the preparation to treat patients with covid-19 , we may be exposed to defaults under our lease financing arrangements . moreover , usage-based arrangements generally contain no minimum payments ; therefore , customers may exit such arrangements without paying a financial penalty to us . as a result of the covid-19 pandemic , we anticipate that some customers will exit such arrangements or seek to amend the terms of our operating lease and usage-based arrangements with them . for some operating lease arrangements , our customers are provided with the right to purchase the leased system at certain points during and or at the end of the lease term . revenue generated from customer purchases of systems under operating lease arrangements ( “ lease buyouts ” ) was $ 52.2 million , $ 92.8 million , and $ 48.8 million for the years ended december 31 , 2020 , 2019 , and 2018 , respectively . we expect that revenue recognized from customer exercises of the buyout options will fluctuate based on the timing of when , and if , customers choose to exercise their buyout options . systems revenue system placements are driven by procedure growth in most markets . in geographies where da vinci procedure adoption is in an early stage or system placements are constrained by regulation , system sales will precede procedure growth . system placements also vary due to seasonality largely aligned with hospital budgeting cycles . we typically place a higher proportion of annual system placements in the fourth quarter and a lower proportion in the first quarter as customer budgets are reset . systems revenue is also affected by the proportion of system placements under operating lease and usage-based arrangements , recurring operating lease and usage-based revenue , operating lease buyouts , product mix , asps , trade-in activities , and customer mix . systems revenue declined 12 % to $ 1.18 billion in 2020. systems revenue grew 19 % to $ 1.35 billion in 2019 and 21 % to $ 1.13 billion in 2018. based on the factors outlined in the covid-19 pandemic section above , the ability to forecast 56 table of contents future system shipments has been significantly disrupted and , therefore , we believe that historical system shipment trends may not be a good indicator of future system shipments . procedure mix / products our da vinci surgical systems are generally used for soft tissue surgery for areas of the body between the pelvis and the neck , primarily in general surgery , gynecologic surgery , urologic surgery , cardiothoracic surgery , and head and neck surgery . within these categories , procedures range in complexity from cancer and other highly complex procedures to less complex procedures for benign conditions . cancer and other highly complex procedures tend to be reimbursed at higher rates than less complex procedures for benign conditions . thus , hospitals are more sensitive to the costs associated with treating less complex , benign conditions . our strategy is to provide hospitals with attractive clinical and economic solutions across the spectrum of procedure complexity . our fully featured da vinci xi surgical system with advanced instruments ( including da vinci energy and endowrist and sureform stapler products ) and our integrated table motion product targets the more complex procedure segment . our da vinci x surgical system is targeted towards price sensitive markets and procedures . our da vinci sp surgical system complements the da vinci xi and x surgical systems by enabling surgeons to access narrow workspaces . procedure seasonality more than half of da vinci procedures performed are for benign conditions , most notably hernia repairs , hysterectomies , and cholecystectomies . these benign procedures and other short-term elective procedures tend to be more seasonal than cancer operations and surgeries for other life-threatening conditions . seasonality in the u.s. for procedures for benign conditions typically results in higher fourth quarter procedure volume when more patients have met annual deductibles and lower first quarter procedure volume when deductibles are reset . seasonality outside the u.s. varies and is more pronounced around local holidays and vacation periods . as a result of the factors outlined in the covid-19 pandemic section above , including the recommendations of authorities to defer elective procedures , historical procedure patterns may be disrupted . distribution channels we provide our products through direct sales organizations in the u.s. , europe ( excluding spain , portugal , italy , greece , and most eastern european countries ) , china , japan , south korea , india , and taiwan . in 2018 , we began direct operations in india and taiwan . in january 2019 , our intuitive-fosun joint venture began direct sales for da vinci products and services in china . in the remainder of our ous markets , we provide our products through distributors . regulatory activities overview our products must meet the requirements of a large and growing body of

sources and uses of cash our principal source of liquidity is cash provided by operations and by the issuance of common stock through the exercise of stock options and our employee stock purchase program . cash and cash equivalents plus short- and long-term investments increased by $ 1.02 billion to $ 6.87 billion as of december 31 , 2020 , from $ 5.85 billion as of december 31 , 2019 , primarily from cash provided by our operations and proceeds from stock option exercises and employee stock purchases , partially offset by capital expenditures , taxes paid related to net share settlements of equity awards , and share repurchases . cash and cash equivalents plus short- and long-term investments increased by $ 1.02 billion to $ 5.85 billion as of december 31 , 2019 , from $ 4.83 billion as of december 31 , 2018 , primarily from cash provided by our operations , partially offset by capital expenditures and share repurchases . our cash requirements depend on numerous factors , including market acceptance of our products , the resources we devote to developing and supporting our products , and other factors . we expect to continue to devote substantial resources to expand procedure adoption and acceptance of our products . we have made substantial investments in our commercial operations , product development activities , facilities , and intellectual property . based upon our business model , we anticipate that we will continue to be able to fund future growth through cash provided by our operations . we believe that our current cash , cash equivalents , and investment balances , together with income to be derived from the sale of our products , will be sufficient to meet our liquidity requirements for the foreseeable future .


 Write a concise suspicious activity report of the following text delimited by triple backquotes. Return your response as a formal report which covers the key points highlighting the location,dates,entity names and account holder information in chronological order of the text.
     ```sources and uses of cash our principal source of liquidity is cash provided by operations and by the issuance of common stock through the exercise of stock options and our employee stock purchase program . cash and cash equivalents plus short- and long-term investments increased by $ 1.02 billion to $ 6.87 billion as of december 31 , 2020 , from $ 5.85 billion as of december 31 , 2019 , primarily from cash provided by our operations and proceeds from stock option exercises and employee stock purchases , partially offset by capital expenditures , taxes paid related to net share settlements of equity awards , and share repurchases . cash and cash equivalents plus short- and long-term investments increased by $ 1.02 billion to $ 5.85 billion as of december 31 , 2019 , from $ 4.83 billion as of december 31 , 2018 , primarily from cash provided by our operations , partially offset by capital expenditures and share repurchases . our cash requirements depend on numerous factors , including market acceptance of our products , the resources we devote to developing and supporting our products , and other factors . we expect to continue to devote substantial resources to expand procedure adoption and acceptance of our products . we have made substantial investments in our commercial operations , product development activities , facilities , and intellectual property . based upon our business model , we anticipate that we will continue to be able to fund future growth through cash provided by our operations . we believe that our current cash , cash equivalents , and investment balances , together with income to be derived from the sale of our products , will be sufficient to meet our liquidity requirements for the foreseeable future .
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 Suspicious Activity Report : these multi-port instruments are generally robotically controlled and provide end effectors ( tips ) that are similar to those used in either open or laparoscopic surgery . we offer advanced instrumentation for the da vinci xi and da vinci x platforms , including da vinci energy and da vinci stapler products , to provide surgeons with sophisticated , computer-aided tools to precisely and efficiently interact with tissue . da vinci x and da vinci xi surgical systems share the same instruments whereas the da vinci si surgical system uses instruments that are not compatible with da vinci x or da vinci xi systems . we currently offer nine core instruments on our da vinci sp surgical system . we plan to expand the sp instrument offering over time . training technologies include our intuitive simulation products , our intuitive telepresence remote case observation and telementoring tools , and our dual console for use in surgeon proctoring and collaborative surgery . during the first quarter of 2019 , the fda cleared our ion endoluminal system to enable minimally invasive biopsies in the lung . our ion system extends our commercial offering beyond surgery into diagnostic procedures with this first application . we are introducing the ion system in the u.s. in a measured fashion while we optimize training pathways and our supply chain and collect additional clinical data . we are early in the launch and have placed 36 ion systems for commercial use as of december 31 , 2020. ion systems are not included in our da vinci surgical system installed base . we currently have 3 ion systems placed with hospitals for gathering clinical data in addition to the systems placed for commercial use . the success of new product introductions depends on a number of factors including , but not limited to , pricing , competition , market and consumer acceptance , the effective forecasting and management of product demand , inventory levels , the management of manufacturing and supply costs , and the risk that new products may have quality or other defects in the early stages of introduction . 52 table of contents covid-19 pandemic procedures prior to the spread of covid-19 in the first quarter of 2020 , we experienced procedure growth trends consistent with those experienced in the fourth quarter of 2019 , including strength in general surgery , growth in mature procedures in the u.s. , and growth in ous urology . beginning in january 2020 , we saw a substantial reduction in da vinci procedures in china and , by early february 2020 , procedures per week in china had declined by approximately 90 % compared to the weekly procedure rates experienced in early january 2020. as the covid-19 pandemic subsided in china in march 2020 , da vinci procedure volume began to recover and , by the end of the first quarter of 2020 , china procedures per week were approximately 70 % of the early january 2020 weekly procedure rate . as the covid-19 pandemic spread to western europe and the u.s. , we experienced a significant decline in da vinci procedures in the last half of march 2020 , and procedures per week in the u.s. declined to approximately 65 % of the weekly procedure rate experienced earlier in the first quarter of 2020. in april 2020 , procedures per week in the u.s. continued to decline , reaching approximately 30 % of pre-covid-19 levels . in may and june , u.s. procedures began a recovery phase , as covid-19 cases dropped and elective procedures were permitted , and , by the middle of june , had grown to nearly the same level as that measured in the first two weeks of the first quarter of 2020. however , in the last two weeks of june and into july , with the resurgence of covid-19 cases , some regions postponed elective procedures , and we experienced a corresponding decline in da vinci procedures . the impact of covid-19 in europe during the second quarter varied by country with procedures in italy , france , and the uk declining more steeply , while germany experienced a year-over-year increase in procedures . during the second quarter of 2020 , china procedures per week continued to increase to a level consistent with the early january 2020 weekly procedure rate . in the third quarter of 2020 , procedures recovered slowly in the u.s. , leveling off near pre-covid-19 levels towards the end of the quarter . outside of the u.s. , da vinci procedures varied in the third quarter of 2020 , depending on the spread and or resurgence of covid-19 . for example , covid-19 had a less significant impact in germany where da vinci procedures grew at mid-single digits relative to the third quarter of 2019 , while it had a more significant impact in the u.k. where da vinci procedures declined year over year . procedures in china grew significantly year over year in the third quarter of 2020 , while regional covid-19 outbreaks resulted in year-over-year procedure growth rates in japan slowing somewhat relative to earlier in the year . the covid-19 pandemic has also affected the volumes of certain procedure types differently . for example , patient concerns over exposure to covid-19 and the fact that prostate cancer can be slow growing , combined with lower prostate diagnoses and treatments , have caused the number of dvp procedures to decline in the third quarter of 2020 relative to the third quarter of 2019. da vinci bariatric procedures grew significantly year over year in the third quarter of 2020 due to our optimized instrument set and focus by our sales organization and may also have benefited from certain patients prioritizing weight loss as obesity is a significant covid-19 risk factor . story_separator_special_tag as of december 31 , 2020 , a total of 901 da vinci surgical systems were installed at customers under operating lease or usage-based arrangements . our system leasing and usage-based models provide customers with flexibility regarding how they acquire or obtain access to our systems . we believe that these alternative financing structures have been effective and well-received , and we are willing to expand the proportion of these structures based on customer demand . as revenue for operating leases and usage-based systems is recognized over time , total systems revenue growth is reduced in a period when the number of operating lease and usage-based placements increases as a proportion of total system placements . our exposure to the credit risks relating to our lease financing arrangements may increase if our customers are adversely affected by changes in healthcare laws , coverage and reimbursement , economic pressures or uncertainty , or other customer-specific factors . in addition , as customers divert significant resources to the treatment of or the preparation to treat patients with covid-19 , we may be exposed to defaults under our lease financing arrangements . moreover , usage-based arrangements generally contain no minimum payments ; therefore , customers may exit such arrangements without paying a financial penalty to us . as a result of the covid-19 pandemic , we anticipate that some customers will exit such arrangements or seek to amend the terms of our operating lease and usage-based arrangements with them . for some operating lease arrangements , our customers are provided with the right to purchase the leased system at certain points during and or at the end of the lease term . revenue generated from customer purchases of systems under operating lease arrangements ( “ lease buyouts ” ) was $ 52.2 million , $ 92.8 million , and $ 48.8 million for the years ended december 31 , 2020 , 2019 , and 2018 , respectively . we expect that revenue recognized from customer exercises of the buyout options will fluctuate based on the timing of when , and if , customers choose to exercise their buyout options . systems revenue system placements are driven by procedure growth in most markets . in geographies where da vinci procedure adoption is in an early stage or system placements are constrained by regulation , system sales will precede procedure growth . system placements also vary due to seasonality largely aligned with hospital budgeting cycles . we typically place a higher proportion of annual system placements in the fourth quarter and a lower proportion in the first quarter as customer budgets are reset . systems revenue is also affected by the proportion of system placements under operating lease and usage-based arrangements , recurring operating lease and usage-based revenue , operating lease buyouts , product mix , asps , trade-in activities , and customer mix . systems revenue declined 12 % to $ 1.18 billion in 2020. systems revenue grew 19 % to $ 1.35 billion in 2019 and 21 % to $ 1.13 billion in 2018. based on the factors outlined in the covid-19 pandemic section above , the ability to forecast 56 table of contents future system shipments has been significantly disrupted and , therefore , we believe that historical system shipment trends may not be a good indicator of future system shipments . procedure mix / products our da vinci surgical systems are generally used for soft tissue surgery for areas of the body between the pelvis and the neck , primarily in general surgery , gynecologic surgery , urologic surgery , cardiothoracic surgery , and head and neck surgery . within these categories , procedures range in complexity from cancer and other highly complex procedures to less complex procedures for benign conditions . cancer and other highly complex procedures tend to be reimbursed at higher rates than less complex procedures for benign conditions . thus , hospitals are more sensitive to the costs associated with treating less complex , benign conditions . our strategy is to provide hospitals with attractive clinical and economic solutions across the spectrum of procedure complexity . our fully featured da vinci xi surgical system with advanced instruments ( including da vinci energy and endowrist and sureform stapler products ) and our integrated table motion product targets the more complex procedure segment . our da vinci x surgical system is targeted towards price sensitive markets and procedures . our da vinci sp surgical system complements the da vinci xi and x surgical systems by enabling surgeons to access narrow workspaces . procedure seasonality more than half of da vinci procedures performed are for benign conditions , most notably hernia repairs , hysterectomies , and cholecystectomies . these benign procedures and other short-term elective procedures tend to be more seasonal than cancer operations and surgeries for other life-threatening conditions . seasonality in the u.s. for procedures for benign conditions typically results in higher fourth quarter procedure volume when more patients have met annual deductibles and lower first quarter procedure volume when deductibles are reset . seasonality outside the u.s. varies and is more pronounced around local holidays and vacation periods . as a result of the factors outlined in the covid-19 pandemic section above , including the recommendations of authorities to defer elective procedures , historical procedure patterns may be disrupted . distribution channels we provide our products through direct sales organizations in the u.s. , europe ( excluding spain , portugal , italy , greece , and most eastern european countries ) , china , japan , south korea , india , and taiwan . in 2018 , we began direct operations in india and taiwan . in january 2019 , our intuitive-fosun joint venture began direct sales for da vinci products and services in china . in the remainder of our ous markets , we provide our products through distributors . regulatory activities overview our products must meet the requirements of a large and growing body of

