Year US Dollars 1975 -9585678.75376 1976 -8919222.77893 1977 -7958305.611 1978 -16245850.9786 1979 -19530628.21373 1980 -20055795.94625 1981 -26060675.70673 1982 -22988132.67066 1983 -30744144.14414 1984 -23352347.52084 1985 -25285983.65808 1986 -30117647.05882 1987 -27504551.18331 1988 -46942664.27412 1989 -40094557.01232 1990 -35460719.2468 1991 -49780965.60234 1992 -34742038.45297 1993 -38299855.49133 1994 -56033176.7914 1995 -77702415.61098 1996 -83497037.09717 1997 -64776414.72101 1998 -74908310.99196 1999 -39161812.09326 2000 -49739125.12964 2001 -58204475.78173 2002 -67626250.11469 2003 -75431427.92075 2004 -85455980.83785 2005 -102161688.07718 2006 -109178455.87137 2007 -137320916.76237 2008 -126575178.87205 2009 -158979047.8017 2010 -176760848.1518 2011 -191959554.60947 2012 -206636733.7306 2013 -190309839.65855 2014 -180264249.84826 2015 -207712109.51572 2016 -187955171.32409