Scientists found that an $800\mathrm{.}00$ mg tablet of acetylsalicylic acid $($C$9$H$8$O$4)$ contains $200\mathrm{.}00$ mg of carbon and $25\mathrm{.}2$ mg of hydrogen. The remaining mass is oxygen. Determine the percent composition of acetylsalicylic acid. $[3$ marks$]$