Year US Dollars adjusted for inflation) 1960 3175.04524 1961 3134.77887 1962 3230.70183 1963 3440.25941 1964 3542.54761 1965 3556.86992 1966 3862.84218 1967 3950.92109 1968 4119.96213 1969 4187.5061 1970 4221.15828 1971 4350.8108 1972 4563.18033 1973 4600.75085 1974 4744.44819 1975 4967.40408 1976 5362.4973 1977 5421.24946 1978 5380.77604 1979 5228.53725 1980 4986.68681 1981 5111.20014 1982 5174.05955 1983 5310.34194 1984 5544.20358 1985 5659.40092 1986 5936.07721 1987 6375.47509 1988 6404.02378 1989 6308.83887 1990 6774.62597 1991 6709.09836 1992 6932.12472 1993 7343.33115 1994 6889.81699 1995 7315.41315 1996 7731.42516 1997 8186.50639 1998 8244.76341 1999 7842.84764 2000 8237.60871 2001 7631.65013 2002 8003.73838 2003 8332.0275 2004 9009.88607 2005 9692.12957 2006 10251.37718 2007 10638.06334 2008 10599.63117 2009 9973.6633 2010 10672.40016 2011 11683.60448 2012 12052.72008 2013 12866.09535 2014 13312.4552 2015 13898.74884 2016 14117.43687 2017 14933.26521