Year current US$ 1970 529.0549943227156 1971 583.5025992099521 1972 637.9350660012426 1973 819.757099464893 1974 1021.8187516788744 1975 1044.0523310381427 1976 1127.0255964368282 1977 1211.9021543778033 1978 1334.7225199855704 1979 1510.408442878744 1980 1756.2734624214866 1981 1991.7746947576295 1982 1788.6227855371033 1983 1498.994733938594 1984 1474.0315366264979 1985 1425.503824331645 1986 1430.4992158889197 1987 1470.323585722681 1988 1636.8237767948938 1989 1757.4336159210065 1990 2002.1043037700576 1991 2174.825997548458 1992 2351.039276669671 1993 2705.251475279067 1994 3115.3432679911602 1995 3322.5157505659367 1996 3558.6331789184064 1997 3838.1513267137025 1998 3790.7865638700587 1999 3299.8428614503537 2000 3568.362447222157 2001 3440.757015308153 2002 3006.449855324146 2003 2992.7956165724795 2004 3379.1407210892653 2005 4019.597597663291 2006 4692.095486386921 2007 5538.962808783599 2008 6358.16819393827 2009 5901.664793158971 2010 7177.798753408841 2011 7937.643157128153 2012 7879.969743943525 2013 8063.171637527095 2014 8145.941510561368 2015 6867.809222815651 2016 6598.995671079145 2017 7301.983099588401 2018 6982.294074194456 2019 6847.182625209696 2020 5721.123448512059 2021 6358.946731682525