I need help with this problem

A stock analyst plots the price per share of a certain common stock as a function of time and finds that it can be approximated by the function S(t) = 40 + 6e-0.2, where t is the time (in years) since the stock was purchased. Find the average price of the stock over the first five years. The average price of the stock is $ . (Round to the nearest cent as needed.)