Year	Number
1960	1249
1961	1249
1962	1249
1963	1249
1964	1249
1966	1249
1967	1249
1968	1249
1969	1249
1971	1249
1972	1249
1973	1249
1974	1249
1981	8000
1982	8000
1983	8000
1984	8000
1985	8000
1986	15000
1987	15000
1988	15000
1989	15000
1990	15000
1991	15000
1992	15000
1993	15000
1994	15000
1995	15000
1996	15000
1997	15000
1998	23000
1999	24000
2000	25000
2001	35000
2002	35000
2003	100000
2004	100000
2005	100000
2006	100000
2007	100000
2008	100000
2009	100000
2010	100000
2011	90000
2012	70000
2013	64000
2014	57200
2015	51000
2016	48000
2018	74800
2019	91000
2020	91000
2021	91000
2022	91000