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	61
1997	300
1998	297
1999	600
2000	5000
2001	15000
2002	32000
2003	41500
2004	61900
2005	96900
2006	120000
2007	150000
2008	180000
2009	200000
2010	399290
2011	478860
2012	501077
2013	510783
2014	516540
2015	533336
2016	575650