Year	Number
1960	10314
1961	10587
1962	10909
1963	11246
1964	11597
1965	11957
1966	12320
1967	12688
1968	13067
1969	13452
1970	13790
1971	14063
1972	14315
1973	14565
1974	14819
1975	15107
1976	15424
1977	15736
1978	16049
1979	16363
1980	16793
1981	17406
1982	18091
1983	18805
1984	19550
1985	20325
1986	21130
1987	21974
1988	22853
1989	23762
1990	24538
1991	25117
1992	25656
1993	26198
1994	26750
1995	27298
1996	27837
1997	28368
1998	28874
1999	29360
2000	29657
2001	29674
2002	29570
2003	29419
2004	29233
2005	29024
2006	28793
2007	28541
2008	28265
2009	27960
2010	27660
2011	27358
2012	27014
2013	26627
2014	26199
2015	25739
2016	25240
2017	24701
2018	24134
2019	23535
2020	22921
2021	22289
2022	21873
2023	21685