Year	Number
1990	29209
1991	24756
1992	24348
1993	23997
1994	23706
1995	23376
1996	23043
1997	22641
1998	22156
1999	21624
2000	21053
2001	20492
2002	19978
2003	22411
2004	19129
2005	18805
2006	18518
2007	18193
2008	17879
2009	17668
2010	17468
2011	17759
2012	19144
2013	19368
2014	19089
2015	19096
2016	18288
2017	18457
2018	18928
2019	17809
2020	17244
2021	17519
2022	17304