Beginning in the third quarter of 2012, certain operators in North America reduced activity levels in response to lower commodity  prices which had begun to impact their project economics. While the average U.S. rig count reported by Baker Hughes increased in  2012 over the average rig count in 2011, by the end of 2013 the active rigs working were less than the 2012 average rig count. This  decrease in activity led to virtually no growth in activity levels in North America. Outside of the U.S., the worldwide rig count at the  end of 2013 was up versus the end of 2012, while activity in certain parts of the world such as West Africa, East Africa, the Middle  East and the Asia Pacific region continued to exhibit some strength. As a result of slow global economic growth from 2009 through 2013, in conjunction with moderate commodity prices, our clients did  not materially increase their activity levels. In spite of this, our revenue increased more than 9% over 2012, with operating income  increasing over 12%. Results of operations as a percentage of applicable revenue are as follows (dollars in thousands): Results of Operations *Percentage based on applicable revenue rather than total revenue. “NM” means not meaningful. (1)  Excludes depreciation. 18 2013 2012 2011 2013 /  2012 2012 /  2011 % Change Revenue: Services (1) $ 765,428 71.3% $ 693,895 70.7% $ 621,752 68.5% 10.3% 11.6% Product Sales (1)  308,080  28.7% 287,185 29.3% 285,896 31.5% 7.3% 0.5% TOTAL REVENUE  1,073,508 100.0% 981,080 100.0% 907,648 100.0% 9.4% 8.1% OPERATING EXPENSES: Cost of services* (1)  444,963 58.1% 413,086 59.5% 395,303 63.6% 7.7% 4.5% Cost of product sales* (1)  218,005 70.8% 208,733 72.7% 198,066 69.3% 4.4% 5.4% Total cost of services and product sales  662,968 61.8% 621,819 63.4% 593,369 65.4% 6.6% 4.8% General and administrative expenses (1) 51,988 4.8% 43,185 4.4% 41,141 4.5% 20.4% 5.0% Depreciation and amortization 25,471 2.4% 22,917 2.3% 23,303 2.6% 11.1% (1.7)% Other (income) expense, net (338) —% (4,121) (0.4)% (919) (0.1)% NM NM OPERATING INCOME  333,419 31.1% 297,280 30.3% 250,754 27.6% 12.2% 18.6% Loss on early extinguishment of debt — —% — —% 1,012 0.1% —% (100.0)% Interest expense 9,317 0.9% 8,820 0.9% 10,900 1.2% 5.6% (19.1)% Income before income tax expense  324,102 30.2% 288,460 29.4% 238,842 26.3% 12.4% 20.8% Income tax expense 80,908 7.5% 71,848 7.3% 54,198 6.0% 12.6% 32.6% Net income  243,194 22.7% 216,612 22.1% 184,644 20.3% 12.3% 17.3% Net income attributable to non-controlling interest 383 —% 541 0.1% (40) —% NM NM Net income attributable to Core Laboratories N.V. $ 242,811 22.6% $ 216,071 22.0% $ 184,684 20.3% 12.4% 17.0% Diluted earnings per share attributable to Core Laboratories N.V. $ 5.28 $ 4.54 $ 3.82 16.3% 18.8% Diluted weighted average common shares outstanding 45,994 47,553 48,393