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	25579000
1982	42766000
1983	52564000
1984	54570000
1985	61267000
1986	174639000
1987	191481000
1988	617485000
1989	20705350000
1990	23270059000
1991	23395042000
1992	24331839000
1993	24167607000
1994	24799403000
1995	25427802000
1996	26255068000
1997	21776508000
1998	22457989000
1999	23274460000
2000	12785239000
2001	12578501000
2002	13267121000
2003	15517154000
2004	17565787000
2005	18530479000
2006	18686347000
2007	23070521000
2008	26435435000
2009	32702629000
2010	44901572000
2011	53886305000
2012	61576671000
2013	65452000000
2014	72429832000
2015	77827377000
2016	86952492000