Year	Number
1969	53634
1970	54406
1971	49477
1972	43246
1973	39400
1974	37333
1975	34999
1976	33171
1977	32591
1978	30814
1979	30121
1980	29518
1981	28449
1982	27963
1983	26838
1984	26108
1985	25744
1986	24955
1987	24525
1988	24268
1989	24051
1990	23760
1991	22797
1992	21917
1993	20946
1994	20104
1995	19420
1996	19120
1997	18849
1998	18737
1999	18513
2000	18764
2001	18755
2002	18840
2003	18960
2004	18738
2005	18569
2006	18817
2007	18769
2008	18139
2009	17260
2010	16540
2011	16271
2012	16229
2013	16014
2014	15889
2015	15559
2016	15148
2017	14649
2018	14328
2019	14040
2020	13298
2021	12664
2022	11806