Year	Number
1971	53298
1972	57124
1973	58644
1974	62514
1976	69590
1977	71865
1978	78149
1979	75265
1980	78695
1981	83431
1982	91081
1983	99542
1984	103510
1985	111915
1986	121104
1987	132776
1988	140950
1989	156944
1990	166663
1991	173383
1992	183071
1993	182140
1994	193771
1996	202797
1997	206934
1998	210876
1999	230043
2000	245122
2001	256286
2002	285366
2003	306062
2004	355732
2005	401040
2006	442596
2007	499325
2008	558076
2009	615772
2010	687735
2011	796458
2012	891604
2013	960219
2014	1032009
2015	1082127
2016	1064638
2017	1048487
2018	1061581