Year	Number
1960	8625
1961	8834
1962	9050
1963	9273
1964	9427
1965	9678
1966	9919
1967	10258
1968	10643
1969	11033
1970	11422
1971	11682
1972	12085
1973	12432
1974	12769
1975	13055
1976	13405
1977	13673
1978	13952
1979	14375
1980	14859
1981	15413
1982	15845
1983	16256
1984	16593
1985	16828
1986	16940
1987	17094
1988	17238
1989	17290
1990	17277
1991	17167
1992	17038
1993	16942
1994	16978
1995	17023
1996	17018
1997	17021
1998	17038
1999	17054
2000	17154
2001	17308
2002	17510
2003	17686
2004	17854
2005	17976
2006	18038
2007	18084
2008	18110
2009	18191
2010	18483
2011	18602
2012	18694
2013	18693
2014	18723
2015	18715
2016	18749
2017	18728
2018	18633
2019	18636
2020	18615
2021	18644
2022	18570
2023	18542