The following income statement and vertical analysis data are available

The following income statement and vertical analysis data are available for Robbins Audio Products:

The following income statement and vertical analysis data are available

Required:
1. Suggest why net income declined from $273,200 to $41,600 while the cost of goods sold percentage decreased each year and selling and administrative expenses remained nearly constant.
2. Determine what could cause sales to decline while the gross margin percentageincreases.