Vertical analysis (common-size) percentages for Vallejo Companys sales, cost of goods sold, and expenses are listed here. Vertical Analysis 2012 2011 2010 Sales 100 % 100 % 100 % Cost of goods sold 61.4 64.6 66.7 Expenses 24.8 26.7 29.0 Did Vallejos net income as a percent of sales increase, decrease, or remain unchanged over the 3-year period? Provide numerical support for your answer.