Input (grade 12): Byrd led the Democratic caucus as Senate Majority Leader from 1977 to 1981 and 1987 to 1989, and as Senate Minority Leader from 1981 to 1987.
Output (grade 6): He served as majority leader from 1977 to 1981 and again from 1987 to 1989. He was also minority leader from 1981 to 1987.