The past five monthly returns for $K$ and Company are $2\mathrm{.}28$ percent, $2\mathrm{.}64$ percent, $-1\mathrm{.}05$ percent, $4\mathrm{.}25$ percent, and $9\mathrm{.}25$ percent. What is the average monthly return?

$3\mathrm{.}47$ percent

$1\mathrm{.}62$ percent

$1\mathrm{.}45$ percent

$3\mathrm{.}89$ percent