I think I've condensed it down:
WHO ARE 'ORDAINED MINISTERS'?
1950 - All baptized persons - g95 5/22 p.22 'I Was Convinced I Had Found The Meaning Of Life' par. 2
1951 - All dedicated persons, even before baptism - w51 11/1 p.672 Questions From Readers
1952 - All publishers - w52 1/1 p.18 par. 17
1954 - All baptized persons - w54 3/1 'The Meaning of Baptism' p.139
1955 - All publishers - w55 12/15 p.742 par.6
1955 - All dedicated persons - w55 11/1 p.665 par.10 & 13 and p.670 par.27
1957 - All baptized persons - w57 8/15 p.487 'Recognised and Certified by Man' par.4
1961 - All publishers - w61 1/1 p.18 par.5
1962 - All baptized persons - w62 10/15 p.626 'Who Ordains Jehovah's Witnesses?' par.1
1975 - Only men with responsibilities in the cong - WT 75 12/1 p.733 par. 22
1976 - Only men with responsibilities in the cong - 05/1976 KM Question Box
1981 - All baptized persons, specifically including women - w81 3/15 'Who Are God's Ministers?' p.15 par.3
1984 - All dedicated persons - Song Book (1984) Song 202 To God We Are Dedicated
1987 onwards - All baptized persons - w87 5/15 'Zealous at 70 Years of Age' p.27 par.2
Splash