| Year | Count |
|---|---|
| 1969 | 12 |
| 1971 | 10 |
| 1972 | 22 |
| 1973 | 32 |
| 1974 | 42 |
| 1975 | 36 |
| 1976 | 37 |
| 1977 | 61 |
| 1978 | 66 |
| 1979 | 58 |
| 1980 | 56 |
| 1981 | 62 |
| 1982 | 53 |
| 1983 | 62 |
| 1984 | 56 |
| 1985 | 58 |
| 1986 | 38 |
| 1987 | 39 |
| 1988 | 58 |
| 1989 | 76 |
| 1990 | 74 |
| 1991 | 75 |
| 1992 | 100 |
| 1993 | 62 |
| 1994 | 90 |
| 1995 | 68 |
| 1996 | 81 |
| 1997 | 101 |
| 1998 | 136 |
| 1999 | 113 |
| 2000 | 132 |
| 2001 | 188 |
| 2002 | 150 |
| 2003 | 170 |
| 2004 | 219 |
| 2005 | 243 |
| 2006 | 221 |
| 2007 | 217 |
| 2008 | 230 |
| 2009 | 299 |
| 2010 | 264 |
| 2011 | 335 |
| 2012 | 310 |
| 2013 | 289 |
| 2014 | 329 |
| 2015 | 367 |
| 2016 | 370 |
| 2017 | 425 |
| 2018 | 376 |
| 2019 | 434 |
| 2020 | 447 |
| 2021 | 594 |
| 2022 | 554 |
| 2023 | 548 |
| 2024 | 548 |