Statistics by the workplace:
| Year of reporting | Count |
|---|---|
| 1966 | 1 |
| 1979 | 1 |
| 1980 | 4 |
| 1982 | 1 |
| 1983 | 2 |
| 1984 | 2 |
| 1985 | 8 |
| 1986 | 8 |
| 1987 | 7 |
| 1988 | 10 |
| 1989 | 20 |
| 1990 | 62 |
| 1991 | 60 |
| 1992 | 85 |
| 1993 | 101 |
| 1994 | 533 |
| 1995 | 684 |
| 1996 | 647 |
| 1997 | 1138 |
| 1998 | 1462 |
| 1999 | 1629 |
| 2000 | 1777 |
| 2001 | 1659 |
| 2002 | 1643 |
| 2003 | 1229 |
| 2004 | 1889 |
| 2005 | 2250 |
| 2006 | 1537 |
| 2007 | 2487 |
| 2008 | 2156 |
| 2009 | 2981 |
| 2010 | 3910 |
| 2011 | 2695 |
| 2012 | 2815 |
| 2013 | 3135 |
| 2014 | 2939 |
| 2015 | 2449 |
| 2016 | 2817 |
| 2017 | 2616 |
| 2018 | 2312 |
| 2019 | 2121 |
| 2020 | 1810 |
| 2021 | 1798 |
| 2022 | 1447 |
| 2023 | 1373 |
| 2024 | 1566 |
| 2025 | 1405 |
| 2026 | 707 |
| 2027 | 1 |