A retail store had sales of $$45,000$ in April and $$56,000$ in May. The store employs eight full$-$time workers who work a $40-$hour week. In April, the store also had seven part$-$time workers at $10$ hours per week, and in May the store had nine part$-$timers at $15$ hours per week $($assume four weeks in each month$).$

Using sales dollars as the measure of output, what is the percentage change in productivity $($output in dollars per labor hour$)$ from April to May?

Note: Round your intermediate calculations and final answer to $2$ decimal places.

$\backslash$table$[[$Change in productivity,$\%$