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	29057000
1995	36689000
1996	44287000
1997	75455000
1998	146135000
1999	273363000
2000	329695000
2001	432797000
2002	540750000
2003	656093000
2004	760244000
2005	757209000
2006	822736000
2007	896726000
2008	997784000
2009	1050652000
2010	1041547000
2011	1055238000
2012	994095000
2013	945386000
2014	907681000
2015	873145000
2016	796402000