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 0 1994 0 1995 0 1996 0 1997 0 1998 0 1999 2408827000 2000 2791206000 2001 2666169000 2002 3166669000 2003 4484509000 2004 5517177000 2005 7007650000 2006 8616903000 2007 11568598000 2008 13108606000 2009 15094224000 2010 14032317000 2011 14126330000 2012 14556921000 2013 15193561000 2014 14107884000 2015 12867426000 2016 10957714000