Year	US Dollars
1970	981948000
1971	1017280000
1972	1050174000
1973	1218592000
1974	1451063000
1975	1631095000
1976	1468084000
1977	1698453000
1978	1443095000
1979	1725517000
1980	1933419000
1981	2335975000
1982	2881167000
1983	3493312000
1984	3636696000
1985	4149646000
1986	4267673000
1987	4776915000
1988	4639060000
1989	4666128000
1990	4790816000
1991	4618745000
1992	4638272000
1993	4425205000
1994	4651072000
1995	4622580000
1996	4101958000
1997	3825328000
1998	3952116000
1999	4034616000
2000	4827989000
2001	5484759000
2002	5608144000
2003	5726995000
2004	6553549000
2005	6627427000
2006	8121071000
2007	10530734000
2008	10437767000
2009	11123713000
2010	14193368000
2011	14331879000
2012	14308800000
2013	12951048000
2014	14077145000
2015	14108990000
2016	14052570000