Year US Dollars 1970 501773000 1971 701049000 1972 939925000 1973 1019657000 1974 1278107000 1975 2104263000 1976 2712756000 1977 3425066000 1978 4166917000 1979 4955504000 1980 6610722000 1981 9179631000 1982 13353768000 1983 17553908000 1984 18737476000 1985 20273081000 1986 21882901000 1987 22841643000 1988 18569336000 1989 16279833000 1990 15329832000 1991 17080598000 1992 20018184000 1993 26148472000 1994 30335877000 1995 34342562000 1996 39673262000 1997 47228241000 1998 42409220000 1999 41976337000 2000 41946128000 2001 45157951000 2002 48343648000 2003 50773204000 2004 60510496000 2005 64911362000 2006 70050746000 2007 84215420000 2008 106896007000 2009 119611354000 2010 133799555000 2011 144898454000 2012 193879982000 2013 188794797000 2014 196587380000 2015 190951399000 2016 200364305000