Year	Number
1971	1064635
1972	1166470
1973	1223615
1974	1231433
1976	1371444
1977	1464404
1978	1559905
1979	1591922
1980	1710610
1981	1681792
1982	1779618
1983	1852530
1984	1980523
1985	2169686
1986	2300052
1987	2412347
1988	2556630
1989	2728961
1990	2780823
1991	2897655
1992	2997900
1993	3216418
1994	3381901
1995	3474742
1997	3427715
1999	4295403
2000	4528727
2001	5297981
2002	5496099
2003	5589959
2004	5265015
2005	5305406
2006	5519620
2007	5650919
2008	5531751
2009	5681860
2010	5890584
2011	6125744
2012	5927789
2013	8292958
2014	8384690
2015	8181061
2016	8259009
2017	8690855