Year US Dollars adjusted for inflation) 1960 1304.69876 1961 1306.59063 1962 1353.03319 1963 1412.20202 1964 1451.18602 1965 1502.79135 1966 1568.7994 1967 1643.75498 1968 1414.69863 1969 1428.91348 1970 1392.75207 1971 1433.11541 1972 1515.18999 1973 1568.61848 1974 1580.58476 1975 1659.8811 1976 1698.97373 1977 1744.63978 1978 1741.63539 1979 1706.07528 1980 1646.41123 1981 1615.67773 1982 1519.16984 1983 1427.24335 1984 1394.99616 1985 1343.77586 1986 1283.09064 1987 1288.90472 1988 1300.64199 1989 1323.78297 1990 1358.24104 1991 1401.90838 1992 1397.17992 1993 1428.36569 1994 1465.80407 1995 1504.39674 1996 1539.34489 1997 1584.1172 1998 1631.57488 1999 1607.21011 2000 1616.53916 2001 1613.41082 2002 1623.51879 2003 1637.80851 2004 1676.22795 2005 1720.09903 2006 1771.9469 2007 1821.79722 2008 1901.8998 2009 1933.7401 2010 1981.1607 2011 2051.15229 2012 2122.38456 2013 2231.47724 2014 2317.25719 2015 2392.98397 2016 2457.62596 2017 2522.79392