You hold an equally$-$weighted $($half invested in each$)$ portfolio consisting of two stocks A and B$,$ whose returns for the past three years are given below.

Year Stock A Stock B

$201828\%-24\%$

$2019-8\%12\%$

$202012\%-8\%$

What are the average return and standard deviation of your portfolio AB$?$ Average return is

$\%,$ standard deviation is

$\%.$ Round your answer to a whole number, e$.$g$.,$ x or xx$.($Hint: Think of portfolio return each year.$)$