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	0
1993	0
1994	0
1995	0
1996	0
1997	0
1998	0
1999	2408827000
2000	2791206000
2001	2666169000
2002	3166669000
2003	4484509000
2004	5517177000
2005	7007650000
2006	8616903000
2007	11568598000
2008	13108606000
2009	15094224000
2010	14032317000
2011	14126330000
2012	14556921000
2013	15193561000
2014	14107884000
2015	12867426000
2016	10957714000