| Year | Count |
|---|---|
| 1930 | 5 |
| 1960 | 10 |
| 1980 | 15 |
| 1981 | 7 |
| 1988 | 12 |
| 1989 | 12 |
| 1991 | 5 |
| 1993 | 5 |
| 1995 | 7 |
| 1996 | 28 |
| 1997 | 29 |
| 1998 | 69 |
| 1999 | 80 |
| 2000 | 34 |
| 2001 | 34 |
| 2002 | 60 |
| 2003 | 50 |
| 2004 | 70 |
| 2005 | 46 |
| 2006 | 33 |
| 2007 | 44 |
| 2008 | 39 |
| 2009 | 28 |
| 2010 | 37 |
| 2011 | 54 |
| 2012 | 35 |
| 2013 | 37 |
| 2014 | 38 |
| 2015 | 10 |
| 2016 | 5 |
| 2017 | 62 |
| 2018 | 80 |
| 2019 | 69 |
| 2020 | 56 |
| 2021 | 37 |
| 2022 | 88 |
| 2023 | 141 |
| 2024 | 131 |