Year	Number
1971	182514
1972	200247
1973	225579
1974	257194
1975	293981
1976	339771
1977	380776
1978	413151
1979	445413
1980	476206
1981	516548
1982	552847
1983	581403
1984	560473
1985	499159
1986	488078
1987	504128
1988	504481
1993	534368
1994	732196
1995	765073
1998	700766
1999	729866
2000	741066
2001	751240
2002	763183
2003	756844
2004	773831
2005	815112
2006	852139
2007	880428
2009	1241900
2010	1313293
2011	1424067
2012	1515121
2013	1591283
2014	1653890
2015	1637495
2016	1637359
2017	1624377
2018	1621831