Given the data table below answer the questions.

This Year Last Year Sales... $8,000,000 $6,000,000 Cost of goods sold.. 4,984,000 3,516,000 Gross margin..... 3,016,000 2,484,000 Selling and administrative expenses: Selling expenses 1,480,000 1,092,000 Administrative expenses. 712,000 618,000 Total expenses 2,192,000 1,710,000 Net operating income 824,000 774,000 Interest expense. 96,000 84,000 Net income before taxes. $ 728,000 $ 690,000 The company's board of directors is surprised to see net income increased by only $38,000 when sales increased by $2,000,000. Required: 1. Express each year's income statement in common-size percentages. 2. Interpret the changes between the two years.