Vertical analysis (common size) percentages for Kochheim Companys sales, cost of goods sold, and expenses are shown below.

Vertical Analysis	2015	2014	2013
Sales	100.0	100.0	100.0
Cost of goods sold	49.3	53.8	55.9
Expenses	23.3	24.5	25.8

(a)Calculate net income.

2015

2014

2013

Net income

(b) Did Kochheims net income as a percent of sales increase, decrease, or remain unchanged over the 3-year period?