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
1991	0
1992	0
1993	0
1994	0
1995	0
1996	2285
1997	3857
1998	5558
1999	7059
2000	8560
2001	10700
2002	15000
2003	17500
2004	48311
2005	75000
2006	100000
2007	300000
2008	874000
2009	1417546
2010	1909078
2011	2400000
2012	2709000
2013	3000000
2014	3358900
2015	3560000
2016	3782000
2017	4018000
2018	4300000
2019	4535000
2020	4818000
2021	4818000