| Year | Count |
|---|---|
| 1978 | 5 |
| 1979 | 12 |
| 1981 | 11 |
| 1986 | 5 |
| 1987 | 10 |
| 1988 | 12 |
| 1989 | 10 |
| 1990 | 42 |
| 1991 | 62 |
| 1992 | 26 |
| 1993 | 61 |
| 1994 | 54 |
| 1995 | 43 |
| 1996 | 47 |
| 1997 | 21 |
| 1998 | 10 |
| 1999 | 22 |
| 2000 | 23 |
| 2001 | 54 |
| 2003 | 49 |
| 2004 | 97 |
| 2005 | 27 |
| 2006 | 67 |
| 2007 | 98 |
| 2008 | 54 |
| 2009 | 153 |
| 2010 | 241 |
| 2011 | 203 |
| 2012 | 258 |
| 2013 | 156 |
| 2014 | 300 |
| 2015 | 704 |
| 2016 | 508 |
| 2017 | 325 |
| 2018 | 200 |
| 2019 | 126 |
| 2020 | 122 |
| 2021 | 141 |
| 2022 | 59 |
| 2023 | 48 |
| 2024 | 38 |