SOLVED:Solve each problem. The total assets of mutual funds operating in the United States, in billions of dollars, for each year during the period 2004 through 2008 are shown in the table. What were the average assets per year during this period? \begin{array}{|c|c|} \hline \text { Year } & {\text { Assets (in billions of dollars) }} \\ {2004} & {8107} \\ {2005} & {8905} \\ {2006} & {10,397} \\ {2007} & {12,000} \\ {2008} & {9601} \\ \hline \end{array}