| 1979 | 1989 | 1996 | 1998 | 2000 | 2001 | 2002 | 2003 |
| 9830 | 32 302 | 36 700 | 36 800 | 37 300 | 37 300 | 32 070 | 32 100 |
| 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 |
| 32 100 | 31 900 | 31 700 | 31 400 | 31 239 | 31 100 | 29 700 | 29 383 |
| 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2020 | 2021 |
| 29 102 | 28 728 | 28 517 | 28 293 | 28 103 | 27 771 | 27 225 | 27051 |
