Year US Dollars 1970 2196026000 1971 2419454000 1972 2671172000 1973 2761258000 1974 3305259000 1975 4170677000 1976 6039467000 1977 8183425000 1978 10772163000 1979 13281602000 1980 17417200000 1981 20785923000 1982 24412641000 1983 24211101000 1984 24356705000 1985 26637311000 1986 28204156000 1987 29784757000 1988 28932156000 1989 28652836000 1990 30579847000 1991 32493341000 1992 33219034000 1993 36142370000 1994 40256580000 1995 39378713000 1996 44001188000 1997 50705832000 1998 53608204000 1999 58480716000 2000 58455894000 2001 58399716000 2002 60064412000 2003 62762528000 2004 61148530000 2005 58692717000 2006 57597470000 2007 59175563000 2008 58269791000 2009 55984122000 2010 65358008000 2011 66114019000 2012 69371698000 2013 66202034000 2014 78558682000 2015 80622659000 2016 77319196000