A surveyor has a stainless steel measuring tape that is calibrated to be $100\mathrm{.}000$ m long $($i$.$e$.,$ accurate to $\backslash$pm $1$ mm$)$ at $20$C$.$ If she measures the distance between two stakes to be $75\mathrm{.}175$ m on a $6$C day, does she need to add or subtract a correction factor to get the true distance? How large, in mm

$,$ is the correction factor?

$.$