Year	Number
1960	9403
1961	9403
1962	9403
1963	9403
1964	9403
1965	17000
1966	17000
1967	17000
1968	17000
1969	17000
1970	24000
1971	24000
1972	24000
1973	24000
1974	24000
1975	31100
1976	29700
1977	28200
1978	29300
1979	30600
1980	33000
1981	35400
1982	36474
1983	36859
1984	37558
1985	38332
1986	39840
1987	40174
1988	40786
1989	41278
1990	47439
1991	52874
1992	56125
1993	55463
1994	57490
1995	59819
1996	61175
1997	65606
1998	75354
1999	78072
2000	85714
2001	87291
2002	87367
2003	77576
2004	75256
2005	65992
2006	70313
2007	78000
2008	78324
2009	82447
2010	88062
2011	88120
2012	88140
2013	77568
2014	86856
2015	89292
2016	82421
2017	80545
2018	63006
2019	80791
2020	89016
2021	59682
2022	29080