Year	US Dollars
1970	135210000
1971	152211000
1972	175659000
1973	215017000
1974	242454000
1975	270144000
1976	309344000
1977	460544000
1978	594683000
1979	668974000
1980	830101000
1981	821554000
1982	864821000
1983	892448000
1984	879967000
1985	1020832000
1986	1157321000
1987	1366792000
1988	1359049000
1989	1410111000
1990	1558244000
1991	1664944000
1992	1708912000
1993	1826230000
1994	2021057000
1995	2238777000
1996	2311682000
1997	2225558000
1998	2438888000
1999	2757064000
2000	2716143000
2001	2591701000
2002	2900922000
2003	3111211000
2004	3443610000
2005	3196003000
2006	870593000
2007	868791000
2008	994624000
2009	1144299000
2010	1020633000
2011	1213419000
2012	1329036000
2013	1560301000
2014	1658234000
2015	1734424000
2016	1846561000