Year current US$ 1971 278.8775362328376 1972 285.6948281604398 1973 338.2770288898707 1974 459.055433163049 1975 469.48571187645604 1976 527.6057866366735 1977 631.6438637469723 1978 570.1995206922453 1979 394.60327707532036 1980 561.973723282451 1981 601.1161208417149 1982 595.2792397975031 1983 646.5871147912352 1984 717.1612137606412 1985 598.729195952532 1986 661.736770542334 1987 894.1786762552306 1988 509.9360776329925 1989 174.71982741165587 1990 215.01009733411144 1991 240.93322955490606 1992 261.80199289674084 1993 262.8439421625033 1994 669.969931216764 1995 727.605435092603 1996 757.6373332083906 1997 771.8026206447395 1998 821.1853881440278 1999 843.824101946643 2000 880.5614310843937 2001 896.4317931076994 2002 874.1202554864303 2003 881.3239819897043 2004 951.4668234365696 2005 1041.2944351838257 2006 1087.1440066614193 2007 1183.4984175639297 2008 1338.257766084975 2009 1284.524053036307 2010 1319.9604696952747 2011 1438.6531843553487 2012 1510.6828780947192 2013 1539.9986640866712 2014 1675.7319401389443 2015 1774.078982209041 2016 1800.6708075500276 2017 1838.8852557296068 2018 1717.295917654365 2019 1666.9767168286583 2020 1582.2517090324375 2021 1694.9866583193589