On January 4, 1978 the price of a sprocket was $23.51. On January 4, 2011 the price of a sprocket was $51.50. Find the average rate of change in the price of a sprocket from 1978 to 2011. Round to the nearest cent.

The average rate of change is $LaTeX: \displaystyle \frac{51.50-23.51}{2011-1978}= 0.85$ dollars per year.