Year	Number
1971	1527266
1972	1535491
1973	1559652
1975	1534110
1976	1469843
1977	1385849
1978	1311244
1979	1257731
1980	1196072
1981	1130414
1982	1130176
1983	1078267
1984	1023926
1985	1080297
1986	1153660
1987	1235393
1988	1314534
1989	1411581
1990	1418564
1991	1731692
1992	1748314
1993	1690903
1994	1601010
1995	1491707
1996	1392656
1997	1317886
1998	1333507
1999	1133683
2000	941308
2001	783331
2002	613379
2003	555484
2004	550928
2005	499077
2006	437510
2007	379705
2008	352839
2009	366356
2010	265628
2011	235594
2012	263138
2013	215085
2014	239256
2016	201738