The returns to a portfolio over the last $7$ years are:

Year

Portfolio Returns

$1$

$3\%$

$2$

$2\%$

$3$

$3\%$

$4$

$12\%$

$5$

$4\%$

$68\%$

$710\%$

The risk$-$free rate is $2\mathrm{.}25\%$ per year. Calculate the Sortino ratio. Note, this question asks for the Sortino and not the Sharpe ratio. Enter your answer as a number rather than a percentage. That is$,$ if your answer is $0\mathrm{.}92,$ then enter $0\mathrm{.}92$ rather than $92\%.$