Year	Number
1985	30631
1986	27617
1987	31519
1988	28735
1989	31656
1990	35495
1991	35716
1992	52908
1993	53303
1994	58467
1995	61825
1996	77115
1997	97099
1998	113514
1999	110720
2000	112236
2001	119766
2002	121265
2003	128373
2004	149656
2005	182260
2006	199151
2007	215273
2008	226425
2009	200505
2010	221028
2011	244038
2012	252513
2013	262756
2014	269446
2015	280378
2016	272408
2017	269760