Input (grade 13): From 1977 to 1989 Byrd was the leader of the Senate Democrats, serving 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.