Question $9$

$5$ pts

Suppose back in $2007,$ the average ticket price to a Rocket's game was $$21$ and now, $15$ years later, it takes $$72$ to see the Rockets play at the arena. What is the growth rate of the ticket price over the $15-$year period? $($Enter you answer in percentage $($without the $\%$ symbol$),$ round your answer to two decimal points$)$