Year	Number
1960	34749
1961	35665
1962	37607
1963	39503
1964	41378
1965	43129
1966	44603
1967	45637
1968	46094
1969	45897
1970	44972
1971	42835
1972	40067
1973	37678
1974	35602
1975	33792
1976	32218
1977	30851
1978	29667
1979	28697
1980	28063
1981	28331
1982	29517
1983	30963
1984	32471
1985	33988
1986	35517
1987	37199
1988	39054
1989	41114
1990	43374
1991	45660
1992	47752
1993	49379
1994	50465
1995	51120
1996	51380
1997	51165
1998	50525
1999	49590
2000	48253
2001	46630
2002	45198
2003	43802
2004	42106
2005	40412
2006	38949
2007	37555
2008	36254
2009	35364
2010	34827
2011	34763
2012	35485
2013	36549
2014	37513
2015	38471
2016	39585
2017	40961
2018	42673
2019	44636
2020	46659
2021	48295
2022	49588
2023	50856