Year	Number
1960	31289
1961	32289
1962	33317
1963	34372
1964	35415
1965	36457
1966	37441
1967	38435
1968	39417
1969	40262
1970	40977
1971	41569
1972	42041
1973	42411
1974	42755
1975	43118
1976	43449
1977	43412
1978	43039
1979	42666
1980	42287
1981	41896
1982	41475
1983	41033
1984	40619
1985	40270
1986	40009
1987	39834
1988	39726
1989	39670
1990	39662
1991	39690
1992	39737
1993	39776
1994	39803
1995	39825
1996	39785
1997	39641
1998	39460
1999	39325
2000	39279
2001	39341
2002	39509
2003	39780
2004	40112
2005	40435
2006	40718
2007	40793
2008	40650
2009	40491
2010	40349
2011	40255
2012	40068
2013	39733
2014	39410
2015	39016
2016	38585
2017	38178
2018	37715
2019	37244
2020	36916
2021	36703
2022	36608
2023	36640