Year current US$ 1960 2.114285172056115 1961 5.440960798120109 1962 7.557210928184345 1963 6.970380660017946 1964 6.784821475773164 1965 11.032061299572389 1966 14.124150565082038 1967 14.99581546328822 1968 13.830126911008486 1969 13.229963179629095 1970 9.50677105118349 1971 15.633859803641926 1972 12.613443663829766 1973 12.266308603037254 1974 17.543427501689596 1975 23.417585836172524 1976 22.698368342114787 1977 28.32896064224569 1978 37.11652443854748 1979 47.2709441730015 1980 66.18019230481917 1981 71.32982982395177 1982 62.04653353981096 1983 69.38368255310517 1984 62.58314646177203 1985 57.01748707715533 1986 51.44014780964735 1987 61.71498710319852 1988 62.812440857893925 1989 76.11944970962786 1990 77.33754135377269 1991 67.40059631223131 1992 77.02957463281496 1993 75.87465754498011 1994 60.51369264706941 1995 58.24477776030814 1996 52.79019214610879 1997 46.38090432057195 1998 31.148662206030956 1999 15.880712669566297 2000 18.597738535369377 2001 27.782320259918738 2002 38.54752910338447 2003 39.70336485322248 2004 48.005825350961736 2005 34.610686651626715 2006 36.01311346806742 2007 59.123804374196666 2008 62.450687733465024 2009 55.256674099125554 2010 126.58527625697577 2011 126.01113376343355 2012 134.4515450614756 2013 154.61882602513091 2014 51.149221984355506 2015 40.82565047208383 2016 52.274575951747124 2017 67.1053454672607 2018 69.953960550276 2019 63.000348303907266 2020 75.80408815810657 2021 78.54639933491623 2022 66.47945671771839