| Year | Count |
|---|---|
| 1965 | 7 |
| 1970 | 5 |
| 1971 | 7 |
| 1972 | 11 |
| 1978 | 6 |
| 1980 | 33 |
| 1981 | 5 |
| 1982 | 23 |
| 1983 | 5 |
| 1984 | 19 |
| 1985 | 32 |
| 1986 | 14 |
| 1987 | 22 |
| 1988 | 33 |
| 1989 | 77 |
| 1990 | 66 |
| 1991 | 47 |
| 1992 | 18 |
| 1993 | 28 |
| 1994 | 17 |
| 1995 | 11 |
| 1996 | 28 |
| 1997 | 5 |
| 1999 | 5 |
| 2001 | 5 |
| 2004 | 5 |
| 2006 | 6 |
| 2007 | 10 |
| 2008 | 16 |
| 2011 | 10 |
| 2014 | 12 |
| 2016 | 12 |