Year US Dollars adjusted for inflation) 1960 191.79118 1961 140.9135 1962 131.96337 1963 142.02196 1964 163.99133 1965 187.27463 1966 201.52324 1967 185.07593 1968 172.91375 1969 196.74013 1970 228.3177 1971 237.81384 1972 240.88189 1973 253.71437 1974 254.26748 1975 271.59948 1976 263.23062 1977 279.32455 1978 307.76619 1979 326.76837 1980 347.88741 1981 361.22471 1982 387.74558 1983 423.5935 1984 481.3646 1985 538.69083 1986 578.18404 1987 635.4946 1988 695.59905 1989 713.68953 1990 730.77249 1991 787.86744 1992 888.911 1993 1000.61181 1994 1118.49958 1995 1227.55641 1996 1335.36268 1997 1443.77474 1998 1542.06413 1999 1645.988 2000 1771.74151 2001 1905.61078 2002 2065.71858 2003 2258.91211 2004 2472.58656 2005 2738.20546 2006 3069.30478 2007 3487.84577 2008 3805.026 2009 4142.03829 2010 4560.51259 2011 4971.54493 2012 5336.06014 2013 5721.69382 2014 6108.23877 2015 6496.62401 2016 6894.46452 2017 7329.0893