Concentration of Risk and Segment Data Concentration of Risk Sales of the Companys products are concentrated among specific customers. During the six months ended February 29, 2020 , the Companys five largest customers accounted for approximately 47% of its net revenue and 72 customers accounted for approximately 90% of its net revenue. Sales to these customers were reported in the Electronics Manufacturing Services (EMS) and Diversified Manufacturing Services (DMS) operating segments. The Company procures components from a broad group of suppliers. Some of the products manufactured by the Company require one or more components that are available from only a single source. Segment Data Net revenue for the operating segments is attributed to the segment in which the service is performed. An operating segments performance is evaluated based on its pre-tax operating contribution, or segment income. Segment income is defined as net revenue less cost of revenue, segment selling, general and administrative expenses, segment research and development expenses and an allocation of corporate manufacturing expenses and selling, general and administrative expenses. Segment income does not include amortization of intangibles, stock-based compensation expense and related charges, restructuring and related charges, distressed customer charges, acquisition and integration charges, impairment on securities, loss on disposal of subsidiaries, settlement of receivables and related charges, impairment of notes receivable and related charges, restructuring of securities loss, goodwill impairment charges, business interruption and impairment charges, net, income (loss) from discontinued operations, gain (loss) on sale of discontinued operations, other expense (excluding certain components of net periodic benefit cost), interest income, interest expense, income tax expense or adjustment for net income (loss) attributable to noncontrolling interests. Transactions between operating segments are generally recorded at amounts that approximate those at which we would transact with third parties. The following table presents the Companys revenues disaggregated by segment (in thousands): Three months ended February 29, 2020 February 28, 2019 EMS DMS Total EMS DMS Total Timing of transfer Point in time $ 986,570 $ 1,141,881 $ 2,128,451 $ 836,863 $ 1,464,832 $ 2,301,695 Over time 2,843,384 1,153,248 3,996,632 2,967,864 797,431 3,765,295 Total $ 3,829,954 $ 2,295,129 $ 6,125,083 $ 3,804,727 $ 2,262,263 $ 6,066,990 Six months ended February 29, 2020 February 28, 2019 EMS DMS Total EMS DMS Total Timing of transfer Point in time $ 2,377,480 $ 3,011,360 $ 5,388,840 $ 1,257,524 $ 3,566,483 $ 4,824,007 Over time 5,870,026 2,371,915 8,241,941 6,050,306 1,698,952 7,749,258 Total $ 8,247,506 $ 5,383,275 $ 13,630,781 $ 7,307,830 $ 5,265,435 $ 12,573,265 The following table sets forth operating segment information (in thousands): Three months ended Six months ended February 29, 2020 February 28, 2019 February 29, 2020 February 28, 2019 Segment income and reconciliation of income before income tax EMS $ 84,829 $ 88,654 $ 189,529 $ 172,749 DMS 74,619 102,405 247,234 271,970 Total segment income $ 159,448 $ 191,059 $ 436,763 $ 444,719 Reconciling items: Amortization of intangibles (13,577 ) (7,777 ) (29,717 ) (15,423 ) Stock-based compensation expense and related charges (15,109 ) (15,697 ) (45,332 ) (32,946 ) Restructuring and related charges (29,604 ) (817 ) (74,855 ) (6,842 ) Distressed customer charge   (14,963 )  Business interruption and impairment charges, net (1)    2,860 Acquisition and integration charges (7,752 ) (12,785 ) (23,886 ) (21,675 ) Impairment on securities (12,205 )  (12,205 )  Other expense (net of periodic benefit cost) (11,277 ) (11,757 ) (24,274 ) (25,307 ) Interest income 5,336 4,760 11,280 9,139 Interest expense (46,183 ) (46,160 ) (91,094 ) (88,812 ) Income before income tax $ 29,077 $ 100,826 $ 131,717 $ 265,713 (1) Charges, net of insurance proceeds of $2.9 million for the six months ended February 28, 2019 , relate to business interruption and asset impairment costs associated with damage from Hurricane Maria, which impacted our operations in Cayey, Puerto Rico. As of February 29, 2020 , the Company operated in 31 countries worldwide. Sales to unaffiliated customers are based on the Company location that maintains the customer relationship and transacts the external sale. The following tables set forth external net revenue, net of intercompany eliminations, and long-lived asset information where individual countries represent a material portion of the total (in thousands): ` Three months ended Six months ended February 29, 2020 February 28, 2019 February 29, 2020 February 28, 2019 External net revenue: Singapore $ 1,216,369 $ 1,588,931 $ 3,247,285 $ 3,907,604 Mexico 1,153,619 1,052,781 2,344,957 2,048,202 China 968,386 1,199,016 2,123,321 2,517,454 Malaysia 505,424 414,433 996,230 793,961 Ireland 181,790 205,480 435,875 281,199 Other 1,035,235 891,648 2,050,948 1,837,335 Foreign source revenue 5,060,823 5,352,289 11,198,616 11,385,755 U.S. 1,064,260 714,701 2,432,165 1,187,510 Total $ 6,125,083 $ 6,066,990 $ 13,630,781 $ 12,573,265 February 29, 2020 August 31, 2019 Long-lived assets: China $ 1,488,548 $ 1,579,904 Mexico 404,896 418,641 Switzerland 217,065 158 Malaysia 208,576 154,386 Singapore 148,583 156,028 Taiwan 118,315 123,608 Hungary 99,435 85,809 Vietnam 93,495 85,728 Other 470,688 462,261 Long-lived assets related to foreign operations 3,249,601 3,066,523 U.S. 1,148,011 1,146,335 Total $ 4,397,612 $ 4,212,858