Year	Number
1970	9224
1971	9746
1972	10074
1973	10275
1974	10355
1975	10232
1976	9950
1977	10001
1978	10123
1979	9978
1980	9629
1981	9790
1982	9897
1983	9820
1984	9607
1985	9678
1986	9922
1987	9728
1988	9631
1989	9819
1991	10134
1992	9931
1993	9873
1994	9911
1995	9885
1996	9886
1997	9747
1998	9738
1999	9931
2000	10025
2001	9782
2002	9623
2003	9477
2004	8906
2005	9204
2006	8942
2007	8864
2008	8744
2009	8624
2010	8670
2011	8695
2012	8701
2013	8682
2014	8812
2015	8974
2016	9007
2017	9037
2018	9258
2019	9383
2020	9509
2021	9441
2022	9538