Year	Number of
1958	2387
1959	2447
1960	2509
1961	2544
1962	2589
1963	2629
1964	2686
1965	2744
1966	2790
1967	2835
1968	2887
1969	2947
1970	3019
1971	3090
1972	3175
1973	3263
1974	3347
1975	3413
1976	3457
1977	3491
1978	3517
1979	3562
1980	3608
1981	3667
1982	3722
1983	3752
1984	3770
1985	3755
1986	3742
1987	3716
1988	3696
1989	3687
1990	3690
1991	3709
1992	3743
1993	3788
1994	3872
1995	3964
1996	4045
1997	4123
1998	4197
1999	4265
2000	4346
2001	4421
2002	4520
2003	4619
2004	4712
2005	4773
2006	4834
2007	4838
2008	4846
2009	4847
2010	4820
2011	4786
2012	4774
2013	4733
2014	4715
2015	4695