Year US Dollars 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 1041777000 1994 1103614000 1995 1277119000 1996 1818416000 1997 1233574000 1998 1489950000 1999 1436805000 2000 1479938000 2001 1498001000 2002 1685420000 2003 1889304000 2004 2829110000 2005 2981489000 2006 3296984000 2007 4174060000 2008 4337476000 2009 5246915000 2010 5159225000 2011 6131376000 2012 6469413000 2013 6736814000 2014 7232873000 2015 6766730000 2016 7382761000