| Year | Count |
|---|---|
| 1964 | 5 |
| 1965 | 5 |
| 1966 | 21 |
| 1967 | 19 |
| 1968 | 55 |
| 1969 | 114 |
| 1970 | 82 |
| 1971 | 99 |
| 1972 | 130 |
| 1972 | 5 |
| 1973 | 107 |
| 1974 | 184 |
| 1975 | 143 |
| 1976 | 119 |
| 1977 | 131 |
| 1978 | 125 |
| 1979 | 193 |
| 1980 | 558 |
| 1981 | 637 |
| 1982 | 606 |
| 1983 | 535 |
| 1984 | 610 |
| 1985 | 656 |
| 1986 | 434 |
| 1987 | 438 |
| 1988 | 540 |
| 1989 | 1,073 |
| 1990 | 368 |
| 1990 | 7 |
| 1991 | 414 |
| 1992 | 294 |
| 1993 | 215 |
| 1994 | 197 |
| 1995 | 212 |
| 1995 | 5 |
| 1996 | 179 |
| 1997 | 156 |
| 1998 | 121 |
| 1999 | 110 |
| 2000 | 62 |
| 2001 | 37 |
| 2002 | 22 |
| 2003 | 57 |
| 2004 | 56 |
| 2005 | 26 |
| 2006 | 38 |
| 2007 | 18 |
| 2008 | 10 |
| 2009 | 14 |
| 2011 | 15 |
| 2012 | 6 |