Year	Number
1970	453001
1971	477618
1972	513699
1973	537303
1974	572967
1975	627059
1976	699547
1977	791930
1978	929832
1979	1095055
1980	1151748
1981	1226130
1982	1249293
1983	1321667
1984	1374770
1985	1427261
1986	1474141
1987	1525039
1988	1578081
1989	1651800
1990	1697943
1991	1710715
1992	1703997
1993	1719854
1994	1833783
1995	1862728
1996	1930917
1997	1963401
1998	2212033
1999	2277813
2000	2374178
2001	2484775
2002	2539682
2003	2287589
2004	2383129
2005	2412334
2006	2491302
2007	2554120
2008	2566702
2009	2645384
2010	2651043
2011	2639703
2012	2580488
2013	2687492
2014	2633128
2015	2644115
2016	2707496
2017	2726802
2018	2724885