Year	Number
1973	2266342
1974	2279555
1975	2252560
1976	2152617
1977	2143268
1978	2085566
1979	2006376
1980	2030373
1981	2192855
1982	2152476
1983	2176994
1984	1922339
1985	1918635
1986	1757288
1987	1666289
1988	1514988
1989	1568816
1990	1527240
1991	1431559
1992	1524341
1993	1616756
1994	1678987
1995	1709382
1996	1600790
1997	1616709
1998	1284970
1999	1157279
2000	1209134
2001	1067770
2002	952266
2003	782766
2004	795116
2005	829447
2006	835629
2007	760851
2008	631381
2009	675881
2010	597058
2011	563561
2012	548064
2013	485046
2014	559057
2015	504009
2016	515543
2017	528231
2018	645153