Earlier quoted context omitted.
Both F-15s lost in the 1st Gulf War were the air-to-ground focused F-15E Strike Eagles. https://rjlee.org/air/ds-aaloss/
per wiki, f-15e was first produced in 1987, so there were very few in service at that time, and most of ground strikes were carried by other aircrafts.
Source is the Gulf War Airpower Survey, page 184 (PDF page 205): https://apps.dtic.mil/sti/tr/pdf/ADA273996.pdf