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	98
1998	1349
1999	2192
2000	2056
2001	2126
2002	57541
2003	82365
2004	172421
2005	323853
2006	483000
2007	900000
2008	1897628
2009	2599000
2010	3668625
2011	4742879
2012	5395540
2013	7006300
2014	8236400
2015	8959000
2016	7471802
2017	8778884
2019	12119000
2020	14239000
2021	14239000