Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

1990

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1991

YES

N/A

YES

YES

YES

YES

N/A

YES

YES

N/A

N/A

N/A

1992

N/A

YES

YES

YES

YES

N/A

YES

YES

N/A

YES

N/A

N/A

1993

N/A

N/A

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

1994

YES

YES

YES

YES

YES

YES

N/A

N/A

YES

YES

N/A

N/A

1995

YES

N/A

YES

YES

YES

YES

YES

YES

YES

YES

N/A

YES

1996

YES

N/A

YES

N/A

YES

YES

YES

YES

YES

YES

N/A

YES

1997

N/A

N/A

N/A

YES

N/A

N/A

N/A

N/A

YES

N/A

N/A

N/A

1998

N/A

N/A

N/A

YES

YES

N/A

YES

N/A

YES

N/A

N/A

N/A

1999

YES

N/A

N/A

N/A

YES

YES

YES

YES

YES

YES

YES

YES