Year US Dollars adjusted for inflation) 1977 184943154.5658 1978 206715583.20938 1979 168588642.74888 1980 192630537.54858 1981 215908721.78022 1982 224835299.68666 1983 230887181.87199 1984 243416029.25657 1985 246542855.72556 1986 263992511.37962 1987 283841295.70625 1988 308135321.25382 1989 307386040.6023 1990 323538864.35951 1991 325505757.07959 1992 332170021.76848 1993 337753613.88323 1994 342587966.69292 1995 349353116.75814 1996 358582268.10061 1997 363928076.69109 1998 382044733.52991 1999 384655225.33517 2000 386098878.53174 2001 387925524.04015 2002 381124567.93563 2003 410422425.45583 2004 423761746.26116 2005 423387808.82532 2006 435791748.537 2007 463338169.7699 2008 496331284.9696 2009 490525414.25522 2010 493824407.40741 2011 492683617.07212 2012 487394618.52553 2013 484433053.87997 2014 505882235.85466 2015 493013933.98665 2016 506021862.86935 2017 484700482.82015