Consider the following table for a period of six years:

a$-1.$ Calculate the arithmetic average returns for large$-$company stocks and T$-$bills over this time period.

Note: Do not round intermediate calculations and enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

a$-2.$ Calculate the standard deviation of the returns for large$-$company stocks and T$-$bills over this time period.

Note: Do not round intermediate calculations and enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$