Year current US$ 1971 253.33954561523285 1972 284.8284293955853 1973 366.6655083293756 1974 435.0063480384805 1975 520.3265633859359 1976 598.3281242010587 1977 773.6235846890532 1978 916.7858224181489 1979 994.6892676425635 1980 1059.9416461276608 1981 824.1414848977564 1982 711.9763484276751 1983 594.8780956450709 1984 593.7540794043126 1985 569.5829141360247 1986 750.9552716273648 1987 785.9028926908196 1988 772.4836834743538 1989 674.7426740722265 1990 709.382113197661 1991 680.4056145489665 1992 708.4216720296248 1993 672.9007186852567 1994 505.73277983508234 1995 656.8359949599247 1996 694.5179787644827 1997 660.2971903226139 1998 703.0519855506498 1999 665.2912286973781 2000 528.2273628606335 2001 531.832914901961 2002 569.5340144206393 2003 674.4414690435065 2004 740.2024071444913 2005 791.3772604420035 2006 794.2612152565706 2007 904.2111369435152 2008 1058.7422843284696 2009 1059.6737818052409 2010 1070.9502322354047 2011 1047.2789087661945 2012 1109.5762714038328 2013 1260.8533747247484 2014 2020.672247324646 2015 1835.537821409253 2016 1846.7729627161602 2017 1918.4515870685573 2018 2098.2320680677462 2019 2079.949481242538 2020 2126.8481003580328 2021 2334.270589552566