Year	US Dollars
1970	55285000
1971	61994000
1972	63328000
1973	310167000
1974	363341000
1975	369679000
1976	388731000
1977	618201000
1978	973265000
1979	1281913000
1980	1523265000
1981	1727221000
1982	2058186000
1983	2339563000
1984	2345278000
1985	3033152000
1986	3721751000
1987	4340608000
1988	4353869000
1989	4193909000
1990	4684042000
1991	4840917000
1992	5356381000
1993	5314118000
1994	6541951000
1995	5734906000
1996	5173712000
1997	5461770000
1998	5510861000
1999	5907562000
2000	5875094000
2001	5728354000
2002	6357145000
2003	7063886000
2004	7058878000
2005	6674250000
2006	6845838000
2007	7668353000
2008	7526241000
2009	8104248000
2010	8216712000
2011	8191699000
2012	7840286000
2013	7251180000
2014	6266049000
2015	6657380000
2016	6453002000