Year	Number
1971	672455
1972	689139
1973	697540
1974	700364
1975	691700
1976	676554
1977	672390
1978	682519
1979	699852
1981	647029
1982	683089
1983	712249
1984	721209
1985	708522
1986	694659
1987	668890
1988	633509
1989	599705
1990	566762
1991	545814
1992	537996
1993	528750
1994	538612
1995	538743
1996	541671
1997	659263
1998	662647
1999	654511
2000	644956
2001	630680
2002	603843
2003	566581
2004	534366
2005	502831
2006	473269
2007	462820
2008	459899
2009	460486
2010	463357
2011	468273
2012	477413
2013	491828
2014	510613
2015	534932
2016	557455
2017	575980
2018	583522
2019	581823
2020	571922
2021	563645