Year current US$ 1973 104.88308976052129 1974 158.90897921098846 1975 239.24700179472262 1976 121.18971099439057 1977 110.76760321408305 1978 150.277959912437 1979 174.13488842050776 1980 198.6543518197233 1981 220.30521076530167 1982 195.95917936247906 1983 183.70163228673476 1984 192.18057055065046 1985 218.36968119406583 1986 208.71416966202372 1987 228.7085120267004 1988 244.1691150064428 1989 258.83458257634203 1990 277.3646086699614 1991 266.9952054760059 1992 268.8361867779697 1993 276.96305748947947 1994 277.7452209141035 1995 306.0197772876315 1996 366.3071510957268 1997 375.1968718249524 1998 381.1798919011244 1999 384.20008844828266 2000 392.89765998592793 2001 388.52983856387664 2002 390.1791648034813 2003 422.0109221439788 2004 450.7535714881847 2005 473.6404169715524 2006 484.90923777847973 2007 537.441578718239 2008 622.1783317265051 2009 691.2005162898164 2010 768.8680503888713 2011 845.2144903131499 2012 870.414581415607 2013 964.944097362783 2014 1082.6609889077674 2015 1205.9318368434328 2016 1590.937290639394 2017 1716.2543919320067 2018 1868.0981250222762 2019 2178.80295519644 2020 2290.392475298202 2021 2541.7117464141197