Year current US$ 1970 327.0832558104579 1971 383.09161520924135 1972 388.29079384253134 1973 730.9109331183023 1974 895.5971141494078 1975 1541.4740363567703 1976 2650.0475301898446 1977 2140.4234042288226 1978 1497.37995259382 1979 805.2656392551329 1980 2775.686184949084 1981 3233.2795899489925 1982 3316.0199472589525 1983 2736.8381045938345 1984 2676.4797145035914 1985 2353.589639373332 1986 2409.336890894098 1987 2069.3794837497567 1988 2791.2099358880087 1989 2431.952305897237 1990 2654.456281244878 1991 2855.0745376206714 1992 2543.1048830454693 1993 1597.3066873546495 1994 1763.528077909915 1995 1872.2712742548067 1996 2246.5171274398945 1997 1982.2429075691002 1998 2034.6492295550622 1999 1940.5854450448999 2000 1354.8877711167343 2001 1838.5164889979258 2002 2053.6596257031397 2003 2536.631889994167 2004 2693.43039820968 2005 3109.210448588161 2006 3107.1364667542566 2007 3446.760238232394 2008 4041.812722159186 2009 3836.756815344031 2010 3740.272300140938 2011 4320.651691079769 2012 4147.473479816519 2013 4678.744151988791 2014 5609.233153976475 2015 4605.245500523417 2016 4420.120801578022 2017 4388.434897630808 2018 4688.690415269213 2019 4527.356122692099 2020 4322.472673550862 2021 4505.83502872903