the trust is not an oil and gas producer . rather , its oil and gas revenue is derived from retained perpetual non-participating oil and gas royalty interests . thus , in addition to being subject to fluctuations in response to the market prices for oil and gas , our oil and gas royalty revenues are also subject to decisions made by the owners and operators of the oil wells to which our royalty interests relate as to investments in and production from those wells . we monitor production reports by the oil and gas companies to assure that we are being paid the appropriate royalties . we review conditions in the agricultural industry in the areas in which our lands are located and seek to keep as much of our lands as possible under lease to local ranchers at competitive rates . in recent years , we have been successful at keeping over 96 % of our land subject to grazing leases . 9 results of operations the trust 's primary sources of income are revenue derived from sales of land , either for cash or a combination of cash and mortgage notes , and revenue derived from the trust 's land and mineral interests . 2013 compared to 2012 total operating and investing revenues in 2013 aggregated $ 44,121,079 , an increase of $ 11,514,188 , or 35.3 % , from the $ 32,606,891 of total operating and investing revenues recorded in 2012. this increase resulted primarily from increases in oil and gas royalty revenue , easements and sundry income , and land sales . these increases were partially offset by a decrease in interest income from notes receivable . earnings per sub-share certificate were $ 3.16 for 2013 compared to $ 2.20 in 2012. the trust purchased and retired 322,056 sub-shares during 2013 , leaving 8,473,202 sub-shares outstanding at december 31 , 2013. land sales in 2013 were $ 6,413,588 compared to $ 5,809,747 in 2012 , an increase of $ 603,841 , or 10.4 % . a total of 10,399 acres were sold in 2013 at an average price of $ 617 per acre , compared to 7,252 acres in 2012 at an average price per acre of $ 801. rentals , royalties and other income ( including interest on investments ) were $ 37,707,491 in 2013 compared to $ 26,797,144 in 2012 , an increase of 40.7 % . oil and gas royalty revenue in 2013 was $ 24,496,851 compared to $ 14,670,915 in 2012 , an increase of 67.0 % . oil royalty revenue was $ 19,930,212 and gas royalty revenue was $ 4,566,639 in 2013. crude oil production from trust royalty wells increased 60.6 % in 2013 from 2012. the average prices per royalty barrel of crude oil for 2013 and 2012 were $ 91.56 and $ 87.56 , respectively . total gas production increased 47.7 % , and the average price of gas increased by 10.6 % in 2013 compared to 2012. grazing lease income in 2013 was $ 494,210 compared to $ 488,694 in 2012. interest revenue ( including interest on investments ) was $ 496,243 in 2013 compared to $ 725,687 in 2012 , a decrease of 31.6 % . interest on notes receivable amounted to $ 484,238 in 2013 compared to $ 706,252 in 2012. at year end 2013 , notes receivable from land sales were $ 3,887,906 compared to $ 8,370,984 at year end 2012. interest on investments amounted to $ 12,005 in 2013 and $ 19,435 in 2012 , respectively . total principal cash payments on notes receivable were $ 4,483,078 in 2013 including $ 2,736,616 of prepaid principal . 10 easement and sundry income revenue in 2013 was $ 12,220,187 compared to $ 10,911,848 in 2012. the increase in easement and sundry income revenue was primarily attributable to increases in the amount of sundry income , sundry lease rental income , and , to a lesser extent , pole line easement income received in 2013 compared to 2012 due to an increase in drilling and exploration activity on land owned by the trust . these increases were partially offset by a decrease in seismic easement income . easement and sundry income is unpredictable and may vary significantly from period to period . taxes , other than income taxes , were $ 1,420,635 in 2013 compared to $ 941,757 in 2012. oil and gas production taxes were $ 1,259,287 in 2013 compared to $ 756,076 in 2012. ad valorem taxes were $ 99,984 in 2013 compared to $ 128,391 in 2012. all other expenses were $ 2,557,866 in 2013 compared to $ 2,342,248 in 2012 . 2012 compared to 2011 total operating revenues and investing revenues in 2012 aggregated $ 32,606,891 , a decrease of $ 1,712,145 , or 5.0 % , from the $ 34,319,036 of total operating revenues and investing revenues recorded in 2011. this decrease resulted primarily from decreases in land sales , interest income from notes receivable and , to a much lesser extent , modest decreases in oil and gas royalty revenue and grazing lease revenue . these decreases were partially offset by an increase in easements and sundry income . earnings per sub-share certificate were $ 2.20 for 2012 compared to $ 2.21 in 2011. the trust purchased and retired 380,156 sub-shares during 2012 , leaving 8,795,258 sub-shares outstanding at december 31 , 2012. land sales in 2012 were $ 5,809,747 compared to $ 11,873,112 in 2011 , a decrease of $ 6,063,365 , or 51.1 % . a total of 7,252 acres were sold in 2012 at an average price of $ 801 per acre , compared to 31,446 acres in 2011 at an average price per acre of $ 378. rentals , royalties and other income ( including interest on investments ) were $ 26,797,144 in 2012 compared to $ 22,445,924 in 2011 , an increase of 19.4 % . oil and gas royalty revenue in 2012 was $ story_separator_special_tag the trust is not an oil and gas producer . rather , its oil and gas revenue is derived from retained perpetual non-participating oil and gas royalty interests . thus , in addition to being subject to fluctuations in response to the market prices for oil and gas , our oil and gas royalty revenues are also subject to decisions made by the owners and operators of the oil wells to which our royalty interests relate as to investments in and production from those wells . we monitor production reports by the oil and gas companies to assure that we are being paid the appropriate royalties . we review conditions in the agricultural industry in the areas in which our lands are located and seek to keep as much of our lands as possible under lease to local ranchers at competitive rates . in recent years , we have been successful at keeping over 96 % of our land subject to grazing leases . 9 results of operations the trust 's primary sources of income are revenue derived from sales of land , either for cash or a combination of cash and mortgage notes , and revenue derived from the trust 's land and mineral interests . 2013 compared to 2012 total operating and investing revenues in 2013 aggregated $ 44,121,079 , an increase of $ 11,514,188 , or 35.3 % , from the $ 32,606,891 of total operating and investing revenues recorded in 2012. this increase resulted primarily from increases in oil and gas royalty revenue , easements and sundry income , and land sales . these increases were partially offset by a decrease in interest income from notes receivable . earnings per sub-share certificate were $ 3.16 for 2013 compared to $ 2.20 in 2012. the trust purchased and retired 322,056 sub-shares during 2013 , leaving 8,473,202 sub-shares outstanding at december 31 , 2013. land sales in 2013 were $ 6,413,588 compared to $ 5,809,747 in 2012 , an increase of $ 603,841 , or 10.4 % . a total of 10,399 acres were sold in 2013 at an average price of $ 617 per acre , compared to 7,252 acres in 2012 at an average price per acre of $ 801. rentals , royalties and other income ( including interest on investments ) were $ 37,707,491 in 2013 compared to $ 26,797,144 in 2012 , an increase of 40.7 % . oil and gas royalty revenue in 2013 was $ 24,496,851 compared to $ 14,670,915 in 2012 , an increase of 67.0 % . oil royalty revenue was $ 19,930,212 and gas royalty revenue was $ 4,566,639 in 2013. crude oil production from trust royalty wells increased 60.6 % in 2013 from 2012. the average prices per royalty barrel of crude oil for 2013 and 2012 were $ 91.56 and $ 87.56 , respectively . total gas production increased 47.7 % , and the average price of gas increased by 10.6 % in 2013 compared to 2012. grazing lease income in 2013 was $ 494,210 compared to $ 488,694 in 2012. interest revenue ( including interest on investments ) was $ 496,243 in 2013 compared to $ 725,687 in 2012 , a decrease of 31.6 % . interest on notes receivable amounted to $ 484,238 in 2013 compared to $ 706,252 in 2012. at year end 2013 , notes receivable from land sales were $ 3,887,906 compared to $ 8,370,984 at year end 2012. interest on investments amounted to $ 12,005 in 2013 and $ 19,435 in 2012 , respectively . total principal cash payments on notes receivable were $ 4,483,078 in 2013 including $ 2,736,616 of prepaid principal . 10 easement and sundry income revenue in 2013 was $ 12,220,187 compared to $ 10,911,848 in 2012. the increase in easement and sundry income revenue was primarily attributable to increases in the amount of sundry income , sundry lease rental income , and , to a lesser extent , pole line easement income received in 2013 compared to 2012 due to an increase in drilling and exploration activity on land owned by the trust . these increases were partially offset by a decrease in seismic easement income . easement and sundry income is unpredictable and may vary significantly from period to period . taxes , other than income taxes , were $ 1,420,635 in 2013 compared to $ 941,757 in 2012. oil and gas production taxes were $ 1,259,287 in 2013 compared to $ 756,076 in 2012. ad valorem taxes were $ 99,984 in 2013 compared to $ 128,391 in 2012. all other expenses were $ 2,557,866 in 2013 compared to $ 2,342,248 in 2012 . 2012 compared to 2011 total operating revenues and investing revenues in 2012 aggregated $ 32,606,891 , a decrease of $ 1,712,145 , or 5.0 % , from the $ 34,319,036 of total operating revenues and investing revenues recorded in 2011. this decrease resulted primarily from decreases in land sales , interest income from notes receivable and , to a much lesser extent , modest decreases in oil and gas royalty revenue and grazing lease revenue . these decreases were partially offset by an increase in easements and sundry income . earnings per sub-share certificate were $ 2.20 for 2012 compared to $ 2.21 in 2011. the trust purchased and retired 380,156 sub-shares during 2012 , leaving 8,795,258 sub-shares outstanding at december 31 , 2012. land sales in 2012 were $ 5,809,747 compared to $ 11,873,112 in 2011 , a decrease of $ 6,063,365 , or 51.1 % . a total of 7,252 acres were sold in 2012 at an average price of $ 801 per acre , compared to 31,446 acres in 2011 at an average price per acre of $ 378. rentals , royalties and other income ( including interest on investments ) were $ 26,797,144 in 2012 compared to $ 22,445,924 in 2011 , an increase of 19.4 % . oil and gas royalty revenue in 2012 was $

liquidity the trust 's principal sources of liquidity are its revenues from oil and gas royalties , lease rentals and receipts of interest and principal payments on the notes receivable arising from its sales of land . in the past , these sources have generated more than adequate amounts of cash to meet the trust 's needs and , in the opinion of management , should continue to do so in the foreseeable future . off-balance sheet arrangements the trust has not engaged in any off-balance sheet arrangements . tabular disclosure of contractual obligations as of december 31 , 2013 , the trust 's known contractual obligations were as follows : replace_table_token_4_th effects of inflation we do not believe that inflation has had a material impact on our operating results . we can not assure you , however , that future increases in our costs will not occur or that any such increases that may occur will not adversely affect our results of operations . 12 critical accounting policies and estimates the preparation of financial statements in conformity with accounting principles generally accepted in the united states of america ( gaap ) requires management to make estimates and assumptions that affect the reported amounts ofassets and liabilities at the date of the financial statements .


 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.
     ```liquidity the trust 's principal sources of liquidity are its revenues from oil and gas royalties , lease rentals and receipts of interest and principal payments on the notes receivable arising from its sales of land . in the past , these sources have generated more than adequate amounts of cash to meet the trust 's needs and , in the opinion of management , should continue to do so in the foreseeable future . off-balance sheet arrangements the trust has not engaged in any off-balance sheet arrangements . tabular disclosure of contractual obligations as of december 31 , 2013 , the trust 's known contractual obligations were as follows : replace_table_token_4_th effects of inflation we do not believe that inflation has had a material impact on our operating results . we can not assure you , however , that future increases in our costs will not occur or that any such increases that may occur will not adversely affect our results of operations . 12 critical accounting policies and estimates the preparation of financial statements in conformity with accounting principles generally accepted in the united states of america ( gaap ) requires management to make estimates and assumptions that affect the reported amounts ofassets and liabilities at the date of the financial statements .
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 Suspicious Activity Report : the trust is not an oil and gas producer . rather , its oil and gas revenue is derived from retained perpetual non-participating oil and gas royalty interests . thus , in addition to being subject to fluctuations in response to the market prices for oil and gas , our oil and gas royalty revenues are also subject to decisions made by the owners and operators of the oil wells to which our royalty interests relate as to investments in and production from those wells . we monitor production reports by the oil and gas companies to assure that we are being paid the appropriate royalties . we review conditions in the agricultural industry in the areas in which our lands are located and seek to keep as much of our lands as possible under lease to local ranchers at competitive rates . in recent years , we have been successful at keeping over 96 % of our land subject to grazing leases . 9 results of operations the trust 's primary sources of income are revenue derived from sales of land , either for cash or a combination of cash and mortgage notes , and revenue derived from the trust 's land and mineral interests . 2013 compared to 2012 total operating and investing revenues in 2013 aggregated $ 44,121,079 , an increase of $ 11,514,188 , or 35.3 % , from the $ 32,606,891 of total operating and investing revenues recorded in 2012. this increase resulted primarily from increases in oil and gas royalty revenue , easements and sundry income , and land sales . these increases were partially offset by a decrease in interest income from notes receivable . earnings per sub-share certificate were $ 3.16 for 2013 compared to $ 2.20 in 2012. the trust purchased and retired 322,056 sub-shares during 2013 , leaving 8,473,202 sub-shares outstanding at december 31 , 2013. land sales in 2013 were $ 6,413,588 compared to $ 5,809,747 in 2012 , an increase of $ 603,841 , or 10.4 % . a total of 10,399 acres were sold in 2013 at an average price of $ 617 per acre , compared to 7,252 acres in 2012 at an average price per acre of $ 801. rentals , royalties and other income ( including interest on investments ) were $ 37,707,491 in 2013 compared to $ 26,797,144 in 2012 , an increase of 40.7 % . oil and gas royalty revenue in 2013 was $ 24,496,851 compared to $ 14,670,915 in 2012 , an increase of 67.0 % . oil royalty revenue was $ 19,930,212 and gas royalty revenue was $ 4,566,639 in 2013. crude oil production from trust royalty wells increased 60.6 % in 2013 from 2012. the average prices per royalty barrel of crude oil for 2013 and 2012 were $ 91.56 and $ 87.56 , respectively . total gas production increased 47.7 % , and the average price of gas increased by 10.6 % in 2013 compared to 2012. grazing lease income in 2013 was $ 494,210 compared to $ 488,694 in 2012. interest revenue ( including interest on investments ) was $ 496,243 in 2013 compared to $ 725,687 in 2012 , a decrease of 31.6 % . interest on notes receivable amounted to $ 484,238 in 2013 compared to $ 706,252 in 2012. at year end 2013 , notes receivable from land sales were $ 3,887,906 compared to $ 8,370,984 at year end 2012. interest on investments amounted to $ 12,005 in 2013 and $ 19,435 in 2012 , respectively . total principal cash payments on notes receivable were $ 4,483,078 in 2013 including $ 2,736,616 of prepaid principal . 10 easement and sundry income revenue in 2013 was $ 12,220,187 compared to $ 10,911,848 in 2012. the increase in easement and sundry income revenue was primarily attributable to increases in the amount of sundry income , sundry lease rental income , and , to a lesser extent , pole line easement income received in 2013 compared to 2012 due to an increase in drilling and exploration activity on land owned by the trust . these increases were partially offset by a decrease in seismic easement income . easement and sundry income is unpredictable and may vary significantly from period to period . taxes , other than income taxes , were $ 1,420,635 in 2013 compared to $ 941,757 in 2012. oil and gas production taxes were $ 1,259,287 in 2013 compared to $ 756,076 in 2012. ad valorem taxes were $ 99,984 in 2013 compared to $ 128,391 in 2012. all other expenses were $ 2,557,866 in 2013 compared to $ 2,342,248 in 2012 . 2012 compared to 2011 total operating revenues and investing revenues in 2012 aggregated $ 32,606,891 , a decrease of $ 1,712,145 , or 5.0 % , from the $ 34,319,036 of total operating revenues and investing revenues recorded in 2011. this decrease resulted primarily from decreases in land sales , interest income from notes receivable and , to a much lesser extent , modest decreases in oil and gas royalty revenue and grazing lease revenue . these decreases were partially offset by an increase in easements and sundry income . earnings per sub-share certificate were $ 2.20 for 2012 compared to $ 2.21 in 2011. the trust purchased and retired 380,156 sub-shares during 2012 , leaving 8,795,258 sub-shares outstanding at december 31 , 2012. land sales in 2012 were $ 5,809,747 compared to $ 11,873,112 in 2011 , a decrease of $ 6,063,365 , or 51.1 % . a total of 7,252 acres were sold in 2012 at an average price of $ 801 per acre , compared to 31,446 acres in 2011 at an average price per acre of $ 378. rentals , royalties and other income ( including interest on investments ) were $ 26,797,144 in 2012 compared to $ 22,445,924 in 2011 , an increase of 19.4 % . oil and gas royalty revenue in 2012 was $ story_separator_special_tag the trust is not an oil and gas producer . rather , its oil and gas revenue is derived from retained perpetual non-participating oil and gas royalty interests . thus , in addition to being subject to fluctuations in response to the market prices for oil and gas , our oil and gas royalty revenues are also subject to decisions made by the owners and operators of the oil wells to which our royalty interests relate as to investments in and production from those wells . we monitor production reports by the oil and gas companies to assure that we are being paid the appropriate royalties . we review conditions in the agricultural industry in the areas in which our lands are located and seek to keep as much of our lands as possible under lease to local ranchers at competitive rates . in recent years , we have been successful at keeping over 96 % of our land subject to grazing leases . 9 results of operations the trust 's primary sources of income are revenue derived from sales of land , either for cash or a combination of cash and mortgage notes , and revenue derived from the trust 's land and mineral interests . 2013 compared to 2012 total operating and investing revenues in 2013 aggregated $ 44,121,079 , an increase of $ 11,514,188 , or 35.3 % , from the $ 32,606,891 of total operating and investing revenues recorded in 2012. this increase resulted primarily from increases in oil and gas royalty revenue , easements and sundry income , and land sales . these increases were partially offset by a decrease in interest income from notes receivable . earnings per sub-share certificate were $ 3.16 for 2013 compared to $ 2.20 in 2012. the trust purchased and retired 322,056 sub-shares during 2013 , leaving 8,473,202 sub-shares outstanding at december 31 , 2013. land sales in 2013 were $ 6,413,588 compared to $ 5,809,747 in 2012 , an increase of $ 603,841 , or 10.4 % . a total of 10,399 acres were sold in 2013 at an average price of $ 617 per acre , compared to 7,252 acres in 2012 at an average price per acre of $ 801. rentals , royalties and other income ( including interest on investments ) were $ 37,707,491 in 2013 compared to $ 26,797,144 in 2012 , an increase of 40.7 % . oil and gas royalty revenue in 2013 was $ 24,496,851 compared to $ 14,670,915 in 2012 , an increase of 67.0 % . oil royalty revenue was $ 19,930,212 and gas royalty revenue was $ 4,566,639 in 2013. crude oil production from trust royalty wells increased 60.6 % in 2013 from 2012. the average prices per royalty barrel of crude oil for 2013 and 2012 were $ 91.56 and $ 87.56 , respectively . total gas production increased 47.7 % , and the average price of gas increased by 10.6 % in 2013 compared to 2012. grazing lease income in 2013 was $ 494,210 compared to $ 488,694 in 2012. interest revenue ( including interest on investments ) was $ 496,243 in 2013 compared to $ 725,687 in 2012 , a decrease of 31.6 % . interest on notes receivable amounted to $ 484,238 in 2013 compared to $ 706,252 in 2012. at year end 2013 , notes receivable from land sales were $ 3,887,906 compared to $ 8,370,984 at year end 2012. interest on investments amounted to $ 12,005 in 2013 and $ 19,435 in 2012 , respectively . total principal cash payments on notes receivable were $ 4,483,078 in 2013 including $ 2,736,616 of prepaid principal . 10 easement and sundry income revenue in 2013 was $ 12,220,187 compared to $ 10,911,848 in 2012. the increase in easement and sundry income revenue was primarily attributable to increases in the amount of sundry income , sundry lease rental income , and , to a lesser extent , pole line easement income received in 2013 compared to 2012 due to an increase in drilling and exploration activity on land owned by the trust . these increases were partially offset by a decrease in seismic easement income . easement and sundry income is unpredictable and may vary significantly from period to period . taxes , other than income taxes , were $ 1,420,635 in 2013 compared to $ 941,757 in 2012. oil and gas production taxes were $ 1,259,287 in 2013 compared to $ 756,076 in 2012. ad valorem taxes were $ 99,984 in 2013 compared to $ 128,391 in 2012. all other expenses were $ 2,557,866 in 2013 compared to $ 2,342,248 in 2012 . 2012 compared to 2011 total operating revenues and investing revenues in 2012 aggregated $ 32,606,891 , a decrease of $ 1,712,145 , or 5.0 % , from the $ 34,319,036 of total operating revenues and investing revenues recorded in 2011. this decrease resulted primarily from decreases in land sales , interest income from notes receivable and , to a much lesser extent , modest decreases in oil and gas royalty revenue and grazing lease revenue . these decreases were partially offset by an increase in easements and sundry income . earnings per sub-share certificate were $ 2.20 for 2012 compared to $ 2.21 in 2011. the trust purchased and retired 380,156 sub-shares during 2012 , leaving 8,795,258 sub-shares outstanding at december 31 , 2012. land sales in 2012 were $ 5,809,747 compared to $ 11,873,112 in 2011 , a decrease of $ 6,063,365 , or 51.1 % . a total of 7,252 acres were sold in 2012 at an average price of $ 801 per acre , compared to 31,446 acres in 2011 at an average price per acre of $ 378. rentals , royalties and other income ( including interest on investments ) were $ 26,797,144 in 2012 compared to $ 22,445,924 in 2011 , an increase of 19.4 % . oil and gas royalty revenue in 2012 was $

