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	35540000
1994	112815000
1995	320987000
1996	438310000
1997	508060000
1998	706603000
1999	1289063000
2000	1585213000
2001	1515369000
2002	1691664000
2003	1941119000
2004	2169228000
2005	2247015000
2006	2798139000
2007	3904857000
2008	4496965000
2009	4569023000
2010	7159486000
2011	7288789000
2012	10330561000
2013	10065089000
2014	11787756000
2015	13216189000
2016	14085341000