Year	Number
1985	30516
1986	27547
1987	31402
1988	28622
1989	31570
1990	35404
1991	35666
1992	52838
1993	53223
1994	58216
1995	61667
1996	76852
1997	96940
1998	113421
1999	110603
2000	112077
2001	119651
2002	121151
2003	128280
2004	149554
2005	182075
2006	198865
2007	215050
2008	226343
2009	200386
2010	220871
2011	243858
2012	252310
2013	262610
2014	269278
2015	280231
2016	272182
2017	269189