Year	Number
1960	21009
1961	21778
1962	22574
1963	23339
1964	24070
1965	24824
1966	25608
1967	26398
1968	27194
1969	28023
1970	28890
1971	29722
1972	30506
1973	31305
1974	32127
1975	32925
1976	33699
1977	34504
1978	35438
1979	36499
1980	37583
1981	38690
1982	39825
1983	40983
1984	42166
1985	43367
1986	44569
1987	45781
1988	46838
1989	47727
1990	48615
1991	49510
1992	50670
1993	52112
1994	53436
1995	54206
1996	54529
1997	54809
1998	55072
1999	55261
2000	55399
2001	55503
2002	55496
2003	55384
2004	55191
2005	54944
2006	54645
2007	54279
2008	53877
2009	53474
2010	53341
2011	53489
2012	53664
2013	53855
2014	54067
2015	54295
2016	54538
2017	54800
2018	55063
2019	55307
2020	55694
2021	56233
2022	56777
2023	57334