Year	Number
1960	9796
1961	10032
1962	10273
1963	10514
1964	10757
1965	11007
1966	11275
1967	11568
1968	11889
1969	12235
1970	12596
1971	12975
1972	13366
1973	13760
1974	14153
1975	14552
1976	14970
1977	15405
1978	15849
1979	16310
1980	16775
1981	17237
1982	17695
1983	18126
1984	18534
1985	18933
1986	19314
1987	19671
1988	20029
1989	20386
1990	20735
1991	21100
1992	21476
1993	21848
1994	22163
1995	22431
1996	22695
1997	22990
1998	23347
1999	23759
2000	24210
2001	24710
2002	25266
2003	25855
2004	26450
2005	27054
2006	27683
2007	28348
2008	29080
2009	29922
2010	30885
2011	31963
2012	33167
2013	34458
2014	35939
2015	37643
2016	39428
2017	41243
2018	43088
2019	44973
2020	46609
2021	47614
2022	48082
2023	48642