• 1980 to 1981 1
• 1982 to 1984 0
• 1985 to 1986 0
• 1987 to 1989 0
• 1990 to 1991 0
• 1992 to 1994 0
• 1995 to 1996 0
• 1997 to 1999 0
• 2000 to 2001 0
• 2002 to 2004 0
• 2005 to 2005 1