The following are the returns of a bond portfolio and the returns of a relevant benchmark index for the past $5$ years:

Year Port. Return $(\%)$ Bench. Return $(\%)$

$18\mathrm{.}089\mathrm{.}53$

$24\mathrm{.}084\mathrm{.}91$

$31\mathrm{.}551\mathrm{.}75$

$46\mathrm{.}977\mathrm{.}92$

$53\mathrm{.}483\mathrm{.}94$

What is the tracking risk of this portfolio based on these $5$ years? Enter answer in percents.