Year	Number of
1990	49610
1991	45480
1992	41220
1993	37060
1994	33590
1995	30870
1996	28910
1997	27500
1998	26520
1999	25620
2000	24640
2001	23330
2002	21840
2003	20660
2004	19550
2005	18820
2006	18340
2007	18000
2008	17550
2009	17100
2010	16440
2011	15850
2012	15110
2013	14270
2014	13490
2015	12800