Year	Number
1960	11675
1961	11852
1962	11975
1963	12060
1964	12108
1965	12106
1966	12055
1967	11897
1968	11648
1969	11386
1970	11112
1971	10822
1972	10565
1973	10352
1974	10146
1975	9945
1976	9686
1977	9395
1978	9156
1979	8972
1980	8854
1981	8841
1982	8853
1983	8838
1984	8816
1985	8740
1986	8596
1987	8411
1988	8251
1989	8259
1990	8586
1991	9259
1992	9728
1993	9833
1994	9913
1995	9912
1996	9883
1997	9922
1998	10021
1999	10159
2000	10261
2001	10274
2002	10225
2003	10139
2004	10029
2005	9969
2006	10003
2007	10078
2008	10167
2009	10250
2010	10217
2011	10048
2012	9874
2013	9742
2014	9651
2015	9588
2016	9530
2017	9463
2018	9375
2019	9260
2020	9055
2021	8765
2022	8467
2023	8178