Year	Number
1960	12807
1961	13028
1962	13237
1963	13447
1964	13645
1965	13843
1966	14008
1967	14181
1968	14433
1969	14712
1970	15073
1971	15489
1972	15862
1973	16178
1974	16390
1975	16663
1976	16790
1977	16847
1978	17013
1979	17157
1980	17302
1981	17363
1982	17553
1983	17646
1984	17698
1985	18249
1986	18885
1987	19360
1988	19929
1989	20568
1990	21256
1991	22293
1992	22855
1993	23476
1994	24187
1995	24905
1996	25677
1997	26463
1998	27201
1999	27923
2000	28730
2001	29656
2002	30554
2003	31383
2004	32163
2005	32834
2006	33295
2007	33861
2008	35076
2009	36683
2010	38193
2011	39658
2012	41155
2013	42587
2014	44071
2015	45545
2016	46701
2017	47947
2018	49579
2019	51434
2020	52443
2021	52691
2022	54591
2023	58113