Use the following table to answer the questions.

$$\begin{array}{|c|c|} \hline {\text { Year }} & {\text { Real GDP (billions of } 2009 \text { dollars) }} \\ \hline {1990} & {\$ 8,955} \\ \hline {1991} & {8,948} \\ \hline {1992} & {9,567} \\ \hline {1993} & {9,521} \\ \hline {1994} & {9,905} \\ \hline \end{array}$$

a. Calculate the growth rate of real GDP for each year from 1991 to $1994 .$

b. Calculate the average annual growth rate of real GDP for the period from 1991 to 1994 .