Year	Number
1970	32198
1971	32685
1972	33079
1973	33442
1974	33629
1975	33434
1976	32686
1977	31346
1978	29499
1979	27357
1980	25254
1981	23377
1982	21704
1983	20266
1984	19110
1985	18311
1986	17855
1987	17687
1988	17739
1989	17874
1990	18024
1991	17979
1992	17644
1993	17160
1994	16569
1995	15792
1996	14884
1997	14011
1998	13308
1999	12822
2000	12413
2001	11993
2002	11630
2003	11258
2004	10902
2005	10645
2006	10398
2007	10122
2008	9851
2009	9632
2010	9426
2011	9139
2012	8802
2013	8469
2014	8148
2015	7846
2016	7494
2017	7069
2018	6562
2019	6120
2020	5771
2021	5461
2022	5268