Year current US$ 1971 124.0444917254439 1972 141.87582677208366 1973 155.58668241525328 1974 179.90862519525106 1975 189.24494748303388 1976 193.03422840088487 1977 241.29035376358289 1978 277.3230422213436 1979 315.0782307771417 1980 356.7149898539672 1981 324.6623814927569 1982 284.915442450859 1983 265.3571115102587 1984 267.9898960769957 1985 258.41193227978425 1986 292.6094481769312 1987 310.90941123319385 1988 312.9721008433745 1989 300.71903427184793 1990 292.7951048153987 1991 266.46556983734456 1992 258.34997651306594 1993 167.82555246725346 1994 207.30820341180313 1995 252.78283846097716 1996 339.6610308836821 1997 366.4254604894243 1998 386.0560782836119 1999 344.8492246329158 2000 331.21475553880407 2001 329.66688542667924 2002 321.2039940565634 2003 345.8341738505283 2004 368.91697718322195 2005 425.62534723241714 2006 581.3851459903957 2007 695.135733196103 2008 763.9659210581472 2009 766.3805625309071 2010 809.3461370083767 2011 830.421081742447 2012 970.685967468284 2013 1023.4653820559297 2014 1102.0331311343966 2015 1126.0099261264147 2016 1311.565013887729 2017 1396.3168606382812 2018 1555.7155860299451 2019 1684.5660606932088 2020 1651.267340345279 2021 1796.8066926433319