Year	Total
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	0
2003	0
2004	500
2005	1300
2006	1600
2007	1800
2009	1000
2010	1600
2011	2130
2012	2800
2013	3400
2014	3800
2015	6600
2016	7600