| Year | Count |
|---|---|
| 1978 | 5 |
| 1979 | 15 |
| 1980 | 11 |
| 1981 | 31 |
| 1982 | 23 |
| 1983 | 49 |
| 1984 | 52 |
| 1985 | 55 |
| 1986 | 92 |
| 1987 | 99 |
| 1988 | 127 |
| 1989 | 184 |
| 1990 | 257 |
| 1991 | 333 |
| 1992 | 494 |
| 1993 | 496 |
| 1994 | 555 |
| 1995 | 600 |
| 1996 | 618 |
| 1997 | 1,506 |
| 1998 | 1,905 |
| 1999 | 1,922 |
| 2000 | 2,342 |
| 2001 | 2,352 |
| 2002 | 1,856 |
| 2003 | 1,756 |
| 2004 | 1,521 |
| 2005 | 1,394 |
| 2006 | 1,331 |
| 2007 | 1,231 |
| 2008 | 1,199 |
| 2009 | 1,095 |
| 2010 | 1,167 |
| 2011 | 983 |
| 2012 | 846 |
| 2013 | 774 |
| 2014 | 674 |
| 2015 | 683 |
| 2016 | 556 |
| 2017 | 444 |
| 2018 | 368 |
| 2019 | 275 |
| 2020 | 199 |
| 2021 | 301 |
| 2022 | 181 |
| 2023 | 125 |
| 2024 | 137 |