Year US Dollars 1967 -34552718.30306 1968 -27063629.02304 1969 -26542482.59159 1970 -20622058.14624 1971 -29245919.7998 1972 -46423485.76108 1973 -71335893.79835 1974 -151638085.17241 1975 -162846010.66945 1976 -94161768.65083 1977 -71637998.98811 1978 -222905770.68891 1979 -243040682.28144 1980 -253692263.71121 1981 -238588459.56394 1982 -205108666.51065 1983 -209675061.80032 1984 -219641900.4446 1985 -357817126.93901 1986 -379081037.89164 1987 -312194920.6852 1988 -383171696.18618 1989 -287892195.90838 1990 -409715100.88708 1991 -409830457.88671 1992 -516422344.77985 1993 -409738432.97102 1994 -365337424.19688 1995 -463396653.1797 1996 -410153041.99531 1997 -253104582.83405 1998 -224004498.6726 1999 -327590214.11595 2000 -309161313.65609 2001 -262529117.63843 2002 -64351524.45909 2003 -333453110.91546 2004 -433230333.33535 2005 -508819395.9028 2006 -284187824.55434 2007 -679800895.86844 2008 -1292222311.79488 2009 -722799454.3679 2010 -1314656242.87015 2011 -1098103890.06542 2012 -607889605.07679 2013 -1985038721.15618 2014 -2227094443.12976 2015 -2037187182.33763 2016 -2327362044.06617 2017 -2900659102.48953