Year US Dollars 1970 2682000 1971 2610000 1972 4380000 1973 9456000 1974 13797000 1975 17392000 1976 22630000 1977 31254000 1978 41242000 1979 52517000 1980 59192000 1981 62601000 1982 65782000 1983 67687000 1984 73525000 1985 75128000 1986 74760000 1987 79617000 1988 74957000 1989 73538000 1990 91807000 1991 113649000 1992 117764000 1993 140499000 1994 154590000 1995 160046000 1996 153446000 1997 138790000 1998 143915000 1999 148000000 2000 139172000 2001 135465000 2002 148294000 2003 168610000 2004 176494000 2005 169098000 2006 165440000 2007 187695000 2008 207365000 2009 252886000 2010 325099000 2011 368309000 2012 422905000 2013 447234000 2014 450184000 2015 437424000 2016 417455000