Year US Dollars 1970 145249000 1971 152514000 1972 161629000 1973 199392000 1974 265056000 1975 349085000 1976 409700000 1977 628092000 1978 894938000 1979 1122625000 1980 1473261000 1981 1670739000 1982 1859905000 1983 2072976000 1984 2197167000 1985 2559363000 1986 3230705000 1987 4036579000 1988 3893078000 1989 3278511000 1990 3750335000 1991 3589291000 1992 3684278000 1993 3843449000 1994 3697802000 1995 3915938000 1996 3786093000 1997 3805576000 1998 4096781000 1999 4000850000 2000 3653475000 2001 3700968000 2002 4118759000 2003 4397900000 2004 3940276000 2005 3861744000 2006 1936524000 2007 2585778000 2008 2850926000 2009 3720889000 2010 3909477000 2011 4325490000 2012 4905679000 2013 5225562000 2014 5619669000 2015 5893172000 2016 6637541000