Year current US$ 1970 1157.2490448884773 1971 1290.7824177730788 1972 1530.244723057133 1973 1924.4473509854938 1974 2136.102121210536 1975 2468.6293637284853 1976 2544.1085780465564 1977 2848.1466797048597 1978 3457.439222676644 1979 4181.706376132824 1980 4669.812179444392 1981 4080.5493998443853 1982 3884.3738563236 1983 3746.38148165606 1984 3581.6414083498225 1985 3686.2959605887945 1986 5042.19992656002 1987 6189.249452686852 1988 6862.541736667047 1989 6958.964624222728 1990 8563.34391392515 1991 8817.312909027967 1992 9566.726470442456 1993 8699.023869007686 1994 9136.754133234012 1995 10474.344838119054 1996 10726.217649120192 1997 10204.45789483491 1998 10561.044679117758 1999 10450.98966142623 2000 9804.587257503395 2001 9844.136531774611 2002 10718.55099691683 2003 13010.363135849155 2004 15167.549648731081 2005 16096.822680552821 2006 17330.257938719307 2007 20103.524001295973 2008 21713.15035656448 2009 19030.806515478223 2010 19523.83002557506 2011 21512.62781725687 2012 20603.647704722698 2013 21426.931265620573 2014 21647.593170850072 2015 18574.89375683287 2016 18447.870733445176 2017 19492.174026419398 2018 20752.762693590397 2019 20344.81085136881 2020 19474.39354566195 2021 21952.97076085774