Calculate the observed risk premium in each year for the large$-$company stocks versus the T$-$bills.

b$-1.$ What was the arithmetic average risk premium over this period?

Note: A negative answer should be indicated by a minus sign. Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16$

b$-2.$ What was the standard deviation of the risk premium over this period?

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

$\backslash$table$[[$b$-1.$ Average risk premium,,$],[$b$-2.$ Risk premium standard deviation,,$]]$