Year	Number
1965	19182
1966	19249
1967	19335
1968	19408
1969	19461
1970	19421
1971	19379
1972	19305
1973	19186
1974	19047
1975	18922
1976	18873
1977	18902
1978	18975
1979	19121
1980	19302
1981	19501
1982	19724
1983	19950
1984	20205
1985	20483
1986	20785
1987	21097
1988	21392
1989	21691
1990	22056
1991	22490
1992	22873
1993	23255
1994	23683
1995	24167
1996	24593
1997	24891
1998	25162
1999	25436
2000	25680
2001	25805
2002	25774
2003	25775
2004	25742
2005	25637
2006	25476
2007	25315
2008	25186
2009	25047
2010	24974
2011	24902
2012	24709
2013	24393
2014	23866
2015	23026
2016	22384
2017	22408
2018	22399
2019	22267
2020	22212
2021	22262
2022	22219