Year	US Dollars
1970	0
1971	0
1972	0
1973	0
1974	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	59702000
1993	1031699000
1994	1247180000
1995	1801129000
1996	2390088000
1997	2929382000
1998	3372049000
1999	5310165000
2000	4947980000
2001	5211415000
2002	5140354000
2003	5321598000
2004	5204731000
2005	4631813000
2006	4513826000
2007	4655757000
2008	5070474000
2009	7027540000
2010	7801789000
2011	8299751000
2012	9119150000
2013	10679165000
2014	13310866000
2015	14854025000
2016	16282526000