Assume these are the stock market and Treasury bill returns for a $5-$year period:

Year Stock Market Return $(\%)$ T$-$Bill Return $(\%)$

$201635\mathrm{.}600\mathrm{.}20$

$201715\mathrm{.}100\mathrm{.}20$

$20185\mathrm{.}000\mathrm{.}20$

$201916\mathrm{.}700\mathrm{.}07$

$202025\mathrm{.}500\mathrm{.}09$

Required:

What was the risk premium on common stock in each year?

What was the average risk premium?

What was the standard deviation of the risk premium? $($Ignore that the estimation is from a sample of data.$)$