| Year | Count |
|---|---|
| 1961 | 5 |
| 1986 | 6 |
| 1987 | 7 |
| 1988 | 8 |
| 1989 | 26 |
| 1990 | 16 |
| 1991 | 34 |
| 1992 | 34 |
| 1993 | 45 |
| 1994 | 86 |
| 1995 | 267 |
| 1996 | 280 |
| 1997 | 304 |
| 1998 | 306 |
| 1999 | 325 |
| 2000 | 357 |
| 2001 | 387 |
| 2002 | 298 |
| 2003 | 412 |
| 2004 | 595 |
| 2005 | 716 |
| 2006 | 1,038 |
| 2007 | 1,243 |
| 2008 | 1,084 |
| 2009 | 1,057 |
| 2010 | 988 |
| 2011 | 959 |
| 2012 | 912 |
| 2013 | 704 |
| 2014 | 545 |
| 2015 | 688 |
| 2016 | 417 |
| 2017 | 387 |
| 2018 | 253 |
| 2019 | 202 |
| 2020 | 184 |
| 2021 | 178 |
| 2022 | 152 |
| 2023 | 87 |
| 2024 | 87 |