Year	Number
1971	186667
1972	201810
1973	222481
1974	265589
1975	337524
1976	420315
1977	535109
1978	645588
1979	759288
1980	825852
1981	837261
1982	826477
1983	774410
1984	773781
1985	793516
1986	807597
1987	800732
1988	775345
1989	769714
1990	728614
1991	672166
1992	597997
1993	520290
1994	459140
1995	445178
1996	460348
1997	500339
1998	537229
1999	556465
2000	587641
2001	609881
2002	638342
2003	666156
2004	671949
2005	668881
2006	657380
2007	645643
2008	637177
2009	609467
2010	605758
2011	583001
2012	574195
2013	570344
2014	631057
2015	630515
2016	624567
2017	611961
2018	587467