Year US Dollars 1970 572133000 1971 542384000 1972 601811000 1973 756432000 1974 730062000 1975 720586000 1976 710689000 1977 1066621000 1978 1278643000 1979 1281957000 1980 1398362000 1981 1538841000 1982 1484228000 1983 1666170000 1984 1963070000 1985 2256459000 1986 2766883000 1987 3313213000 1988 3131102000 1989 3402452000 1990 3880930000 1991 4380167000 1992 4508058000 1993 4886541000 1994 5469146000 1995 5935784000 1996 6442987000 1997 6347318000 1998 6969087000 1999 7103698000 2000 6743347000 2001 6860996000 2002 7640293000 2003 8301007000 2004 7239724000 2005 7334163000 2006 3697633000 2007 5041282000 2008 5461776000 2009 7385000000 2010 9114078000 2011 11224506000 2012 12837232000 2013 16626329000 2014 18361454000 2015 20630861000 2016 21396063000