Samples of retentate and permeate from an ultrafiltration system were sent to an analytical lab for oil and grease analysis. The feed concentration is $4,820$ milligrams per liter $(m\frac{g}{L}$ oil and grease and the permeate concentration is $23m\frac{g}{L}$ oil and grease. What is the percent rejection of oil and grease?

$99\mathrm{.}4\%$

$98\mathrm{.}9\%$

$99\mathrm{.}1\%$

$99\mathrm{.}5\%$