Year	Number
1970	52472
1971	56036
1972	60051
1973	61354
1974	65764
1975	73049
1976	78805
1977	83887
1978	88980
1979	91795
1980	95771
1981	98862
1982	104859
1983	115088
1984	125811
1985	131502
1986	146979
1987	150639
1988	161349
1990	181814
1991	195419
1994	199154
1998	228491
1999	237307
2000	276301
2001	304132
2002	351442
2004	363613
2005	442969
2007	607296
2008	733883
2009	776191
2010	747935
2011	695355
2012	743995
2013	743175
2014	801594
2015	802341
2016	822160
2017	854549