$4.$ Vertical analysis $($common size$)$ percentages for Kocheim Company$$s sales revenue, cost of goods sold, and expenses are shown below.

$201820172016$

Sales revenue $100\mathrm{.}0\%100\mathrm{.}0\%100\mathrm{.}0\%$

Cost of goods sold $60\mathrm{.}262\mathrm{.}463\mathrm{.}5$

Expenses $25\mathrm{.}025\mathrm{.}627\mathrm{.}5$

Did Kocheim$$s net income as of percentage of sales increase, decrease, or remain unchanged over the $3$ years? Provide numerical support for your answer.