Complex sentence: The 1980s and most of the 1990s were mainly down seasons for Tulane, with the lone highlight season coming in 1987, when the Green Wave finished 6--6 under then head coach Mack Brown, and lost to Washington 24--12 in the Independence Bowl.
Split into simpler sentences: The 1980s and most of the 1990s were largely down seasons for Tulane, but there were some highlights. In 1987 the Green Wave finished 6--6 under then head coach Mack Brown before losing to Washington 24--12 in the Independence Bowl.