Year current US$ 1970 263.8906466011786 1971 271.6800540710939 1972 280.4467996644013 1973 375.67816222619524 1974 529.8758407571044 1975 471.4099988979628 1976 544.9217717804044 1977 622.763004104205 1978 804.6211777229587 1979 849.8704171621057 1980 981.8001681020621 1981 1149.5405983344285 1982 1056.0902558197026 1983 1160.62527198687 1984 1438.3794304760631 1985 1236.331988354479 1986 998.0171739166605 1987 1053.1188364152154 1988 1221.8840992027651 1989 1252.5844918863843 1990 1465.1914902813396 1991 1706.2160749653613 1992 2003.2935579368552 1993 2288.1652492297017 1994 2528.186391757632 1995 2966.9222671352745 1996 3296.203456980661 1997 3187.008324802823 1998 2114.5854633634917 1999 2248.5310161531793 2000 2596.9523852461716 2001 2583.9801212840453 2002 2829.2001343117317 2003 2994.7860887546753 2004 3398.339354425258 2005 3816.4853164166107 2006 4307.262222227667 2007 5150.803311023296 2008 5912.478463208354 2009 5234.840667896047 2010 6393.204358178193 2011 7511.852833738011 2012 7702.292787397001 2013 7828.368414913027 2014 7915.030632399749 2015 7055.8904494378985 2016 6983.027839247231 2017 7170.6446429450125 2018 7789.8989303059625 2019 7991.165773069764 2020 7474.005395483819 2021 7867.55481345638