Year current US$ 1971 405.1062821343191 1972 451.26445647211 1973 524.9414654070863 1974 643.2804086894009 1975 714.48777279101 1976 852.1968427592653 1977 1019.2884959440925 1978 1226.8911253697252 1979 1493.1236409006874 1980 1705.4825120225603 1981 1848.8254108504914 1982 1873.9068571826906 1983 1870.5304204256427 1984 1758.8311359484685 1985 1652.7779418106322 1986 2025.7478901233767 1987 2010.280552977589 1988 1742.6917310007707 1989 1117.9197985054004 1990 1048.2250398242163 1991 984.1303134576758 1992 1188.2927703930216 1993 1205.780285346577 1994 1283.3841166349341 1995 1340.3387767172724 1996 1325.7926227728592 1997 1361.4838135853868 1998 1467.6444917831361 1999 1471.658396512039 2000 1558.7185030604187 2001 1630.1705787368278 2002 1687.963498401054 2003 1777.7709331078977 2004 1965.8564236815043 2005 2108.6238071174707 2006 2381.843808591982 2007 2542.548219430422 2008 3205.237798254346 2009 3380.2904438570763 2010 3588.6299267383492 2011 3791.6663862845603 2012 4011.2159598759713 2013 4127.937926176734 2014 3917.0959734295093 2015 3736.502281107789 2016 3668.050476998303 2017 3810.797618960565 2018 3893.3638348985864 2019 3973.991539480878 2020 3833.6140115204057 2021 3905.9067528064784