1988-89
- 10 teams
1987-88
- 11 teams
1986-87
- 12 teams
1985-86
- 11 teams
1984-85
- 12 teams
1983-84
- 12 teams
1982-83
- 14 teams
1981-82
- 15 teams
1980-81
- 15 teams
1979-80
- 14 teams
1978-79
- 12 teams
1977-78
- 12 teams
1976-77
- 11 teams
1975-76
- 10 teams
1974-75
- 9 teams
1973-74
- 6 teams
1972-73
- 6 teams
1971-72
- 5 teams
1970-71
- 8 teams
1969-70
- 6 teams
1968-69
- 4 teams
1967-68
- 3 teams
