Year US Dollars adjusted for inflation) 1980 403.65773 1981 447.53842 1982 451.36077 1983 490.1359 1984 498.7035 1985 504.73655 1986 545.52569 1987 677.5412 1988 688.17998 1989 721.22642 1990 789.21733 1991 785.99245 1992 831.06305 1993 861.19392 1994 915.4099 1995 983.26248 1996 1029.17766 1997 1065.05677 1998 1100.16152 1999 1155.20976 2000 1201.10579 2001 1263.96777 2002 1360.79225 2003 1425.05517 2004 1469.37315 2005 1534.82075 2006 1601.9158 2007 1848.56626 2008 1898.05279 2009 1986.13562 2010 2178.92138 2011 2310.00366 2012 2387.00567 2013 2399.91892 2014 2500.26015 2015 2628.18961 2016 2801.27524 2017 2955.81111