Year current US$ 1971 125.62049784604257 1972 132.67795964277659 1973 149.62846476522998 1974 177.3683785458118 1975 190.40393112122288 1976 194.15072563638645 1977 211.70897839958414 1978 235.77449208770543 1979 256.0698972169209 1980 309.27061784116324 1981 389.67407547748934 1982 375.96136565732513 1983 343.34978503300584 1984 316.76848234823905 1985 323.3553396394934 1986 329.99491752876486 1987 346.93857024366486 1988 356.2127618661099 1989 345.7633919978106 1990 362.3281842104916 1991 336.76790744574606 1992 344.55023733072477 1993 331.98282133474754 1994 364.1986446545472 1995 406.7989169430889 1996 442.0872686315305 1997 455.2184493564579 1998 454.1294228658541 1999 474.50261611817547 2000 473.6822917117605 2001 473.98397014116733 2002 490.68135397743225 2003 542.4526831283789 2004 608.0507146447737 2005 683.3933819546925 2006 791.1383626549273 2007 950.5398586164725 2008 1016.4041640829021 2009 1080.0176000471563 2010 1260.7624607561368 2011 1374.4494927991348 2012 1438.1735839628088 2013 1508.1422315733869 2014 1625.7263903400133 2015 1627.981343990258 2016 1678.4607430484523 2017 1769.14472011601 2018 1824.638164468306 2019 1888.9021964090348 2020 1806.21098152995 2021 1987.7452255696269