AMC 8 2008 Problem 8

Candy sales from the Boosters Club from January through April are shown. What were the average sales per month in dollars?

$\textbf{(A)}\ 60 \textbf{(B)}\ 70 \textbf{(C)}\ 75 \textbf{(D)}\ 80 \textbf{(E)}\ 85$