The statements of earnings for Pruitt Company summarized for a four-year period show the following (amounts in thousands of dollars):

2018 2017 2016 2015 Sales revenue $4,025 $4,450 $4,700 $4,975 Cost of sales 2,505 2,627 2,782 3,113 Gross profit 1,520 1,823 1,918 1,862 Operating expenses 690 713 738 742 Pretax earnings 830 1, 110 1,180 1,120 Income tax expense (40%) 332 444 472 448 Net earnings $ 498 $ 666 $ 708 $ 672