Year US Dollars adjusted for inflation) 1960 1205.26063 1961 1276.47651 1962 1242.73298 1963 1367.32366 1964 1545.87327 1965 1441.02482 1966 1548.58657 1967 1560.95153 1968 1692.16358 1969 1782.17739 1970 1886.62157 1971 1975.73434 1972 1966.84828 1973 1987.8344 1974 1978.00372 1975 2042.96719 1976 2202.09099 1977 2256.93426 1978 2391.92388 1979 2341.66109 1980 1994.71511 1981 1976.28253 1982 1896.96078 1983 1747.9398 1984 1632.64566 1985 1639.95874 1986 1629.99567 1987 1565.43783 1988 1527.15612 1989 1517.06964 1990 1448.03364 1991 1398.22024 1992 1346.79807 1993 1298.84419 1994 1266.5316 1995 1314.11994 1996 1372.7902 1997 1382.62159 1998 1410.73839 1999 1396.99955 2000 1336.42961 2001 1310.28647 2002 1264.22231 2003 1224.96834 2004 1218.12035 2005 1216.20847 2006 1210.66821 2007 1207.08719 2008 1211.62384 2009 1223.51062 2010 1219.7491 2011 1138.66496 2012 1229.7782 2013 1305.70923 2014 1384.91035 2015 1469.73018 2016 1552.86101 2017 1632.67749