Year current US$ 1960 11.810230995703328 1961 8.7437283073953 1962 9.688294511266006 1963 15.081892551628885 1964 8.580679900848 1965 25.01228393086362 1966 14.676458645133444 1967 12.156092457767892 1968 9.006775761669743 1969 11.19429565830939 1970 10.401085127809809 1971 12.507440323474476 1972 7.986791962002152 1973 13.610027965487312 1974 9.440011000420542 1975 12.819359868439129 1976 16.58762590597149 1977 13.26827392543307 1978 11.14435526660094 1979 10.382809405867778 1980 12.43237687511777 1981 12.136237110398525 1982 13.847111781969879 1983 15.22993295897339 1984 28.995468128855777 1985 22.361651142826997 1986 15.776872201970443 1987 16.598244176626206 1988 9.672798345560713 1989 8.33425393880773 1990 40.706655497922256 1991 44.639503718322295 1992 77.14977921243535 1993 30.9530316538847 1994 14.454880154770203 1995 17.138752187284222 1996 20.933711522403872 1997 19.423675988183774 1998 11.111970382853809 1999 8.273532979107104 2000 8.978153193253991 2001 11.375278238532006 2002 9.541844314350735 2003 11.484758938099006 2004 9.54888362952381 2005 8.60288448723833 2006 11.521199443589616 2007 -37.20406728989479 2008 10.139399185274353 2009 18.69727167394595 2010 35.76812908493144 2011 30.075849056166525 2012 13.675602052517803 2013 2.4100131041248565 2014 -49.696652536361796 2015 2.590281415754319 2016 5.615527519400169 2017 10.19271432104438 2018 9.396783483759913 2019 16.656696275420952 2020 33.718362966935985 2021 21.005376485947405 2022 29.52650709353985