Year US Dollars 1970 813520000 1971 857446000 1972 943512000 1973 1030649000 1974 1196330000 1975 1681369000 1976 1893527000 1977 2336026000 1978 2578003000 1979 3039850000 1980 3252572000 1981 3609975000 1982 3662595000 1983 3745392000 1984 3751427000 1985 4487166000 1986 5633311000 1987 6480351000 1988 6694153000 1989 6553432000 1990 6904821000 1991 6958490000 1992 6700066000 1993 6477912000 1994 6808523000 1995 6957805000 1996 7060060000 1997 6659844000 1998 6870439000 1999 5953053000 2000 5811476000 2001 6189777000 2002 6674671000 2003 6874318000 2004 7540235000 2005 5460805000 2006 2375621000 2007 2857153000 2008 3079658000 2009 3774356000 2010 4384218000 2011 5099158000 2012 5857018000 2013 5884844000 2014 7524170000 2015 8742426000 2016 9547794000