Year current US$ 1970 2561.716875421033 1971 2923.6585069787807 1972 3554.264198072542 1973 4704.223712255924 1974 5435.491263836134 1975 6220.91155803545 1976 6788.336003896513 1977 7873.759204090231 1978 9520.870003654074 1979 10810.745531892606 1980 11501.440095393222 1981 9497.464231400916 1982 9145.36123934774 1983 8836.197871512146 1984 8295.564670816519 1985 8111.386181104447 1986 11317.881420821852 1987 13835.52051187706 1988 14596.239161648835 1989 14326.889931141195 1990 17198.460273878223 1991 17656.303221939605 1992 19305.401802869645 1993 18777.693026154375 1994 20271.8478771503 1995 24342.433899434607 1996 24320.397274627125 1997 22413.37005336139 1998 23160.033593154392 1999 23844.124513302355 2000 21979.629741479537 2001 21894.760302732117 2002 23744.07831920581 2003 29386.405683182784 2004 33160.50489134707 2005 34410.375700321965 2006 37261.55601732291 2007 42859.083277703605 2008 45441.87431430438 2009 41457.631379076345 2010 41485.07269013091 2011 44453.57418819673 2012 40527.215084131494 2013 42399.31394891187 2014 43058.08045613373 2015 36999.53244024066 2016 37170.14376385773 2017 40003.30181929814 2018 43940.04239627507 2019 42706.65912580097 2020 41293.75737445937 2021 46419.70712121187