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

$201828\%-20\%$

$2019-8\%16\%$

$202012\%-4\%$

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.$)$