Year	Number
1960	56660
1961	56247
1962	55404
1963	54391
1964	53255
1965	52016
1966	50683
1967	49269
1968	47772
1969	46135
1970	44968
1971	44583
1972	44416
1973	44242
1974	44056
1975	43888
1976	43740
1977	43603
1978	43465
1979	43278
1980	43097
1981	42953
1982	42794
1983	42600
1984	42380
1985	42144
1986	41889
1987	41617
1988	41321
1989	40992
1990	40636
1991	40542
1992	40900
1993	41447
1994	42001
1995	42550
1996	43097
1997	43656
1998	44230
1999	44825
2000	45461
2001	45986
2002	46264
2003	46431
2004	46580
2005	46725
2006	46874
2007	47015
2008	47156
2009	47286
2010	47403
2011	47581
2012	47727
2013	47767
2014	47789
2015	47790
2016	47788
2017	47785
2018	47761
2019	47712
2020	47642
2021	47606
2022	47657
2023	47755