Year	Number
1974	40082
1975	39640
1976	38536
1977	36750
1978	34382
1979	31734
1980	29168
1981	26891
1982	24890
1983	23158
1984	21762
1985	20785
1986	20222
1987	20006
1988	20053
1989	20201
1990	20350
1991	20275
1992	19880
1993	19307
1994	18617
1995	17743
1996	16732
1997	15755
1998	14952
1999	14376
2000	13899
2001	13433
2002	13029
2003	12614
2004	12210
2005	11908
2006	11623
2007	11317
2008	11019
2009	10773
2010	10534
2011	10211
2012	9837
2013	9473
2014	9124
2015	8794
2016	8417
2017	7965
2018	7428
2019	6945
2020	6550
2021	6193
2022	5956