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	0
1997	0
1998	0
1999	0
2000	0
2001	0
2002	25000
2003	200000
2004	600000
2005	1200000
2006	2520366
2007	4668096
2008	7898909
2009	10500000
2010	10215840
2011	13797879
2012	15340115
2013	16807156
2014	18407168
2015	19709038
2016	21602982
2017	23929713
2018	21976355
2019	22580071
2020	22678024
2021	22678024