• 1967 to 1969 2
• 1970 to 1974 0
• 1975 to 1979 3
• 1980 to 1984 35
• 1985 to 1989 7
• 1990 to 1994 16
• 1995 to 1999 20
• 2000 to 2004 11
• 2005 to 2009 29
• 2010 to 2014 21