22 Dialog Semiconductor Plc | Annual report and accounts 2012 |  Section 2 | Business review Financial review “Our rigorous focus on working capital together with sound financial  practices rooted in operational excellence are helping Dialog build a scalable platform for sustainable profitable growth.” Jean‑Michel Richard CFO, Vice President Finance The following tables detail the historical  consolidated statements of the operations of  Dialog for the years ended 31 December 2011  and 2012: In line with previous years, the  key performance indicators of  the business continue to be  revenue growth, profitability  and liquidity. The performance  against these and year-on-year  comparison is detailed in the  following section. 1) 2011 numbers adjusted for purchase price allocation, please refer to note 4 to the consolidated financial statements  Segment reporting Results of operations Revenue in the  Mobile Systems  segment for the year ended 31 December 2012 was  US$638.8 million (2011: US$370.9 million),  representing 82.6% of our total revenue (2011:  70.3%). The 72.2% increase in this sector is  primarily driven by the continuous success of  our growing range of highly integrated power  management solutions for portable devices,  including smartphones, tablets and portable  media players.  Operating profit in the  Mobile Systems segment (see note 24 to the consolidated  financial statements) grew to US$112.3 million  from US$59.8 million achieved in 2011, an  increase of 87.7%. This increased profitability  was primarily driven by higher revenues and by leveraging operating expenses whilst  continuing to improve product margins. Revenues from our  Automotive/Industrial  Applications  segment was US$38.7 million  (2011: US$45.9 million), representing 5.0% of our total revenues (2011: 8.7%). This decrease in revenues is mainly the result of  lower sales volumes in the area of professional  lighting applications, caused by the unfavourable  economic climate in Europe and a decreased level  of investment. Operating profit in the segment  was US$8.1 million (2011: US$9.8 million). Despite  lower revenues, operating profit as a percentage  of revenues remained relatively constant (2012: 20.9% compared to 2011: 21.5%),  demonstrating our abilities to control cost. 2012 2011 1) Change US$000  % of revenues US$000  % of revenues  % Revenues Mobile Systems  638,765 82.6 370,926 70.3 72.2 Automotive/Industrial 38,686 5.0 45,878 8.7 (15.7) Connectivity 96,133 12.4 108,778 20.7 0.0 Corporate Sector  (1) 0.0 1,679 0.3 (100.1) Revenues 773,583 100.0 527,261 100.0 46.7 Cost of sales (480,971) (62.2) (319,073) (60.5) 50.7 Gross profit 292,612 37.8 208,188 39.5 40.6 Selling and marketing expenses  (38,669) (5.0) (32,370) (6.1) 19.5 General and administrative expenses  (33,476) (4.3) (24,442) (4.6) 37.0 Research and development expenses  (127,886) (16.5) (90,046) (17.1) 42.0 Restructuring expenses  (1,549) (0.2) – 0.0 – Other operating income  – 0.0 303 0.1 0.0 Operating profit 91,032 11.8 61,633 11.7 47.7 Interest income and other financial income  1,360 0.2 376 0.1 261.7 Interest expense and other financial expense  (6,466) (0.8) (235) 0.0 2,651.5 Foreign currency exchange gains and losses, net  199 0.0 (352) (0.2) (156.5) Result before income taxes 86,125 11.1 61,422 11.6 40.2 Income tax expense  (23,612) (3.1) (4,070) (0.8) 480.1 Net profit 62,513 8.1 57,352 10.9 9.0