Year current US$ 1968 40390000.3004819 1969 36950000.2935529 1970 43229999.7471273 1971 49870000.384748004 1972 43389999.583363496 1973 57780000.0160933 1974 49670000.154525 1975 78070000.0189245 1976 64110000.0981241 1977 47740000.0374764 1978 56670000.4786253 1979 101790000.267327 1980 183449995.934963 1981 89599999.4203448 1982 81969999.9652803 1983 84450000.1743436 1984 73940000.4856288 1985 78089999.6235967 1986 103499999.67217399 1987 109920000.512153 1988 137139999.520034 1989 132040000.34183301 1990 68739999.8158216 1991 70650000.0059605 1992 72520000.0759214 1993 64450000.083074 1994 35759999.8675287 1995 34729999.7545779 1996 43820000.5348772 1997 39749999.4058162 1998 42879999.9132752 1999 21530000.1911819 2000 21359999.9882281 2001 14150000.078603601 2002 11170000.1228601 2003 17739999.929443 2004 22200000.0290573 2005 25610000.215470802 2006 27419999.953359403 2007 23899999.9649823 2008 28890000.000596 2009 34240000.2703071 2010 34009999.9271333 2011 26800000.211223997 2012 26394436.720758703 2013 23209722.2618759 2014 20296241.9243995 2015 20028172.4514934 2016 15577199.5407995 2017 12853995.548561199 2018 10797056.1869442 2019 13866426.6690612 2020 13561823.643744001 2021 17307177.644223 2022 18179870.98917364