Year constant 2015 US$ 1970 14125.512609112759 1971 14414.115918158825 1972 15029.106008294906 1973 15716.387630183586 1974 15221.273598632333 1975 15118.25528905304 1976 15672.56846875771 1977 16032.124125120401 1978 16650.450908637773 1979 16760.416177451007 1980 16526.57857012711 1981 16704.853399432177 1982 16724.541373860917 1983 16953.746675888997 1984 17684.009393958473 1985 18226.951889280146 1986 18820.527109838844 1987 19366.2277644958 1988 20238.445903035503 1989 20704.690648451196 1990 21066.481617878046 1991 21179.15389229298 1992 21443.141652057635 1993 21454.734697564654 1994 22108.369742486982 1995 22558.35097874557 1996 23115.9748333088 1997 23860.69074810272 1998 24542.41707597859 1999 25135.644718957108 2000 25832.458432593776 2001 26061.79876027622 2002 26205.27721691856 2003 26461.441305558215 2004 27141.25284636634 2005 27572.232798252888 2006 28239.710601423565 2007 28496.630823202475 2008 27693.785514132862 2009 26783.608389012436 2010 27655.43280259772 2011 27916.65826673377 2012 28239.397860233606 2013 28466.67237368731 2014 29035.640587593854 2015 29775.853120553467 2016 30091.991683196935 2017 30695.77513144364 2018 31122.479245811242 2019 31467.576837701425 2020 29709.265027434853 2021 31091.059982132305