Suppose we have the following Treasury bill returns and inflation rates over an eight$-$year period:

Year Treasury Bills Inflation

$111\mathrm{.}11\%13\mathrm{.}91\%$

$212\mathrm{.}0416\mathrm{.}72$

$39\mathrm{.}7210\mathrm{.}97$

$48\mathrm{.}988\mathrm{.}59$

$59\mathrm{.}5410\mathrm{.}97$

$611\mathrm{.}9113\mathrm{.}47$

$714\mathrm{.}8117\mathrm{.}70$

$816\mathrm{.}7117\mathrm{.}66$

Calculate the average return for Treasury bills and the average annual inflation rate $($consumer price index$)$ for this period.

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

Calculate the standard deviation of Treasury bill returns and inflation over this time period.

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

What was the average real return for Treasury bills 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$.,32\mathrm{.}16.$