Year	Number
1970	313371
1971	328595.9
1972	340564.5
1973	398889.4
1974	436221
1975	503337.8
1976	550130.1
1977	608902.7
1978	688998.8
1979	788291.9
1980	879023.9
1981	992157.6
1982	1070729
1983	1145402
1984	1207660
1985	1294335
1986	1262697
1987	1316431
1988	1379401
1989	1347563
1990	1345092
1991	1343565
1992	1347660
1993	1409067
1994	1481816
1995	1534852
1996	1545053
1997	1535891
1998	1516692
1999	1532758
2000	1620412
2001	1673337
2002	1700702
2003	1765684
2004	1810912
2005	1840517
2006	1840496
2007	1844217
2008	2018779
2009	2178198
2010	2388645
2011	2450342
2012	2501548
2013	2564639
2014	2663528
2015	2663822
2016	2667286
2017	2768679
2018	2849107