Year	Number
1960	26000
1961	26000
1962	26000
1963	26000
1964	24000
1965	22000
1966	20000
1967	18000
1968	17000
1969	17000
1970	20000
1971	20000
1972	20000
1973	20000
1974	20000
1975	20000
1976	20000
1977	20000
1978	20000
1979	20000
1980	20000
1981	20000
1982	20000
1983	43000
1984	90600
1985	90600
1986	120000
1987	130000
1988	139783
1989	139783
1990	109654
1991	124457
1992	131069
1993	162386
1994	200774
1995	199194
1996	191159
1997	186719
1998	178782
1999	159504
2000	157206
2001	146480
2002	142170
2003	112148
2004	73383
2005	74889
2006	79895
2007	75055
2008	77016
2009	81346
2010	82620
2011	86603
2012	92869
2013	114172
2014	142197
2015	169516
2016	230158
2017	240954
2018	248210
2019	253787
2020	248372
2021	240854
2022	277726
2023	237632