Year current US$ 1970 166.58738707273292 1971 176.17468334697384 1972 192.12259680660839 1973 237.53102922243116 1974 283.32353457025806 1975 302.67622169892644 1976 316.938092033775 1977 348.6266565717182 1978 368.948258544516 1979 414.2836140680767 1980 476.6904518612217 1981 543.8160168311306 1982 524.2930060404725 1983 492.2374910981144 1984 487.3674801919605 1985 495.3229157119262 1986 508.87791427420945 1987 503.80727013314765 1988 537.6170998171518 1989 557.7792977509572 1990 630.854093964157 1991 650.0040201356277 1992 695.5360704847678 1993 741.3166351497767 1994 814.1271628292178 1995 915.1546242751292 1996 998.6549234912313 1997 1044.8372390781587 1998 1008.5536762598045 1999 968.5246904424741 2000 1028.3786018072744 2001 1025.817140392074 2002 1033.3403959303396 2003 1138.0103128872252 2004 1324.6544790414048 2005 1544.4535833786338 2006 1811.4917991509853 2007 2221.0492303717992 2008 2588.021616641497 2009 2524.486367745627 2010 2972.7298623065367 2011 3360.114331061695 2012 3549.451192898876 2013 3693.6126702439474 2014 3799.6199511094756 2015 3557.359263339945 2016 3547.3518180761607 2017 3851.4283542444214 2018 3972.9328637412746 2019 4015.5690657601463 2020 3805.820226722139 2021 4339.459294632021