Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

1980

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1981

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1982

YES

YES

N/A

YES

YES

YES

YES

YES

YES

YES

YES

YES

1983

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1984

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1985

N/A

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1986

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1987

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1988

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1989

YES

YES

YES

YES

N/A

YES

YES

YES

YES

YES

YES

YES