Year	Number
1990	38159
1991	33648
1992	34547
1993	34458
1994	34102
1995	33584
1996	33046
1997	32432
1998	31740
1999	36828
2000	30304
2001	29431
2002	28466
2003	27436
2004	26474
2005	25678
2006	24991
2007	24514
2008	24051
2009	23546
2010	22921
2011	22279
2012	21594
2013	20855
2014	20162
2015	19609
2016	19264
2017	19174
2018	19330
2019	19556
2020	19842
2021	20170
2022	20477