Year	Number
1966	45940
1967	46907
1968	47900
1969	48661
1970	49072
1971	49258
1972	49265
1973	49121
1974	48856
1975	48614
1976	48403
1977	48113
1978	47729
1979	47359
1980	47587
1981	47987
1982	48771
1983	50211
1984	52102
1985	54381
1986	56634
1987	58379
1988	60001
1989	61181
1990	61593
1991	61577
1992	60847
1993	59841
1994	58177
1995	55568
1996	53735
1997	53299
1998	52828
1999	51817
2000	49719
2001	46845
2002	43785
2003	40786
2004	38172
2005	36317
2006	35158
2007	34397
2008	32870
2009	31889
2010	30880
2011	28906
2012	27332
2013	25689
2014	24280
2015	23183
2016	22150
2017	21439
2018	20967
2019	20596
2020	20246
2021	19976
2022	19754