Year	Number
1960	0
1965	0
1970	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1996	300
1997	205
1998	440
1999	700
2000	1200
2001	2100
2002	5000
2003	22000
2004	29000
2005	51000
2006	51000
2007	64500
2008	74500
2009	75500
2010	80000
2011	77000
2012	76000
2013	77000
2014	65000
2015	73009
2016	76583
2017	76878
2018	71594
2019	65224
2020	62525
2021	56703