PART I As a result of the foregoing, in 2010 compared to 2009: segment income before tax for our domestic fixed  communications business increased by 3.4% from NT$17.4 billion to NT$18.1 billion (US$0.6 billion); segment  income before tax for our mobile communications business decreased by 2.8% from NT$30.2 billion to NT$29.3  billion (US$1.0 billion); segment income before tax for our internet business increased by 5.1% from NT$9.3  billion to NT$9.8 billion (US$0.3 billion); segment income before tax for our international fixed communications  business increased by 4.0% from NT$2.6 billion to NT$2.7 billion (US$91.0 million); and segment loss for our  others business segment decreased by 5.5% from NT$2.3 billion to NT$2.2 billion (US$74.7 million).  Our other income, net decreased by 62.1% from NT$0.8 billion in 2009 to NT$0.3 billion (US$11.0  million) in 2010. This decrease was primarily to a NT$0.2 billion (US$7.4 million) loss on disposal of property,  plant, and equipment, and a NT$0.1 billion (US$5.8 million) net loss on valuation and disposal of financial  instruments, and a NT$0.1 billion (US$3.6 million) net loss on foreign exchange.  Our income tax was NT$12.7 billion in 2009, compared to NT$9.1 billion (US$0.3 billion) in 2010. Our  effective tax rate was 22.3% in 2009 and 15.8% in 2010, primarily due to the reduction of the corporate income  tax rate in the R.O.C. from 25% to 17% effective from 2010. Please refer to “Item 5. Operating and Financial  Review and Prospects—Taxation” for a discussion of the change in tax rate.  As a result of the foregoing, our net income attributable to stockholders of the parent increased by 8.8%  from NT$43.8 billion in 2009 to NT$47.6 billion (US$1.6 billion) in 2010. Our net margin was 22.1% in 2009  and 23.5% in 2010.  Our revenues decreased by 1.6% from NT$201.7 billion in 2008 to NT$198.4 billion in 2009. This  decrease was primarily due to a decrease in operating revenues from domestic fixed communications, mobile  communications and international fixed communications.  78 Domestic  Fixed  Communications Mobile  Communications Internet  International  Fixed  Communications  Others Adjustment Total (in billions of NT$) 85.4  91.4  25.6  17.3  4.2  (20.5 ) 203.4  Segment income before tax 18.1  29.3  9.8  2.7  (2.2 ) — 57.7  For the year ended December 31, 2009 Revenues from external customers 71.5  86.5  23.7  15.2  1.5  — 198.4  Intersegment service revenues 13.7  1.9  0.7  1.5  — (17.8 ) — Interest income — — — — 0.5  — 0.5  Other income — 0.1  0.1  — 0.7  — 0.9  85.2  88.5  24.5  16.7  2.7  (17.8 ) 199.8  Segment income before tax 17.4  30.2  9.3  2.6  (2.3 ) — 57.2  Other Income, Net  Income Tax  Net Income  Revenues  The year ended December 31, 2009 compared with the year ended December 31, 2008 