Year US Dollars 1970 3801000 1971 9158000 1972 12307000 1973 20104000 1974 27554000 1975 34016000 1976 49576000 1977 100530000 1978 112580000 1979 146348000 1980 204542000 1981 278508000 1982 352867000 1983 452493000 1984 470357000 1985 589873000 1986 743900000 1987 985967000 1988 1165408000 1989 1355914000 1990 1626888000 1991 1765334000 1992 1798258000 1993 2003259000 1994 2320468000 1995 2409946000 1996 2398114000 1997 2413516000 1998 2670154000 1999 3030863000 2000 2877903000 2001 2743437000 2002 3001370000 2003 3216534000 2004 3369369000 2005 3191118000 2006 3404460000 2007 3615024000 2008 3697621000 2009 3778430000 2010 3788739000 2011 3828257000 2012 4221259000 2013 4013314000 2014 4166023000 2015 4138852000 2016 4251270000