Year US Dollars 1970 144132000 1971 162143000 1972 184902000 1973 208206000 1974 257138000 1975 310688000 1976 375034000 1977 555084000 1978 723509000 1979 912111000 1980 1056126000 1981 1249022000 1982 1396513000 1983 1510712000 1984 1563671000 1985 1907740000 1986 2173398000 1987 2610091000 1988 2433417000 1989 2459601000 1990 2176253000 1991 2129188000 1992 1690939000 1993 1649954000 1994 2153330000 1995 2617586000 1996 2604083000 1997 2496674000 1998 2826031000 1999 3433333000 2000 3106035000 2001 2867283000 2002 3373052000 2003 6798832000 2004 7376895000 2005 8302217000 2006 9565285000 2007 10714075000 2008 12520041000 2009 13941378000 2010 15902556000 2011 15580877000 2012 16046077000 2013 15709998000 2014 16495045000 2015 16124878000 2016 16323430000