Note: Net profit= Gross profit - Tax. Gross profit = Sales - Expenses. The figures for sales is given at the bottom of the bar chart and the figures for net profit is given on top of the line chart.
If XPL sold $20,000$ units in both $1998$ and $1999,$ by what percentage has the price per unit changed?
- $8.7\%$
- $10.96\%$
- $9.86\%$
- Cannot be determined.