Year	Number
1960	20085
1961	20626
1962	21272
1963	21949
1964	22656
1965	23391
1966	24122
1967	24848
1968	25608
1969	26396
1970	27075
1971	27593
1972	28063
1973	28529
1974	29012
1975	29573
1976	30198
1977	30816
1978	31428
1979	32045
1980	32886
1981	34059
1982	35367
1983	36735
1984	38168
1985	39663
1986	41221
1987	42842
1988	44532
1989	46288
1990	47818
1991	48992
1992	50078
1993	51174
1994	52288
1995	53401
1996	54500
1997	55578
1998	56603
1999	57594
2000	58230
2001	58324
2002	58177
2003	57941
2004	57626
2005	57254
2006	56837
2007	56383
2008	55891
2009	55366
2010	54849
2011	54310
2012	53691
2013	52995
2014	52217
2015	51368
2016	50448
2017	49463
2018	48424
2019	47321
2020	46189
2021	45035
2022	44273
2023	43914