CLB 2018 Annual Report

F-32 20. UNAUDITED SELECTED QUARTERLY RESULTS OF OPERATIONS Summarized below is our unaudited quarterly financial data for the quarters during the years ended December 31, 2018 and 2017 (in thousands, except per share data): Quarter ended 2018 December 31 September 30 June 30 March 31 Services and product sales revenue $ 173,207 $ 182,146 $ 175,475 $ 170,018 Cost of services and product sales 125,694 128,179 123,773 119,318 Other operating expenses (3) 29,535 19,088 18,253 18,384 Operating income 17,978 34,879 33,449 32,316 Interest expense 3,634 3,278 3,296 3,120 Income before income tax expense 14,344 31,601 30,153 29,196 Income tax expense 5,750 9,404 5,020 5,273 Net income from continuing operations 8,594 22,197 25,133 23,923 Net income (loss) from discontinued operations 408 208 (328) (346) Net income 9,002 22,405 24,805 23,577 Net income (loss) attributable to non-controlling interest 167 (7) 53 50 Net income attributable to Core Laboratories N.V. $ 8,835 $ 22,412 $ 24,752 $ 23,527 Per share information: Basic earnings per share (1) (2) $ 0.20 $ 0.51 $ 0.56 $ 0.53 Diluted earnings per share (1) (2) $ 0.20 $ 0.50 $ 0.56 $ 0.53 Weighted average common shares outstanding: Basic 44,226 44,216 44,203 44,179 Diluted 44,401 44,591 44,493 44,463 Quarter ended 2017 December 31 September 30 June 30 March 31 Services and product sales revenue $ 170,111 $ 162,887 $ 158,212 $ 156,609 Cost of services and product sales 119,942 118,361 113,635 113,021 Other operating expenses 17,764 17,857 17,222 20,049 Operating income 32,405 26,669 27,355 23,539 Interest expense 2,717 2,707 2,692 2,618 Income before income tax expense 29,688 23,962 24,663 20,921 Income tax expense 8,016 3,595 3,709 2,929 Net income from continuing operations 21,672 20,367 20,954 17,992 Net income (loss) from discontinued operations (20) 686 1,755 (310) Net income 21,652 21,053 22,709 17,682 Net income (loss) attributable to non-controlling interest (39) (33) 19 24 Net income attributable to Core Laboratories N.V. $ 21,691 $ 21,086 $ 22,690 $ 17,658 Per share information: Basic earnings per share (1) (2) $ 0.49 $ 0.48 $ 0.51 $ 0.40 Diluted earnings per share (1) (2) $ 0.49 $ 0.48 $ 0.51 $ 0.40 Weighted average common shares outstanding: Basic 44,147 44,141 44,164 44,159 Diluted 44,276 44,332 44,374 44,347 (1) Basic earnings per share and Diluted earnings per share are based on Net income attributable to Core Laboratories N.V. (2) The sum of the individual quarterly earnings per share amounts may not agree with the year-to-date earnings per share amounts as each quarterly computation is based on the weighted average number of common shares outstanding during that period. (3) Fourth quarter of 2018 includes charges of $9.9 million of additional stock compensation expenses. See Note 14.