Year US Dollars 1962 1610 1963 1710 1964 1860 1965 2050 1966 2240 1967 2470 1968 2630 1969 2850 1970 3120 1971 3570 1972 4230 1973 5320 1974 6750 1975 8380 1976 9150 1977 9960 1978 11110 1979 13110 1980 15650 1981 16420 1982 15750 1983 14940 1984 15150 1985 15710 1986 17550 1987 20830 1988 23970 1989 25080 1990 26510 1991 27830 1992 30790 1993 30220 1994 30860 1995 32700 1996 35800 1997 37920 1998 36110 1999 35550 2000 36560 2001 38250 2002 39900 2003 44760 2004 54110 2005 63790 2006 69980 2007 78410 2008 87360 2009 87850 2010 88440 2011 90280 2012 99100 2013 104340 2014 104540 2015 93050 2016 82010 2017 75990