Year kg per PPP $ of GDP 1990 0.4648231162370989 1991 0.4262321950778929 1992 0.41286979971039534 1993 0.4256956250040448 1994 0.4153391250928771 1995 0.41165779982518813 1996 0.3975178690816668 1997 0.39394045350831847 1998 0.37800595869819625 1999 0.37094322463849094 2000 0.3527402181581763 2001 0.34961575353515245 2002 0.3569585924195093 2003 0.3814727166274841 2004 0.35598500319300896 2005 0.3435690797442859 2006 0.346413919926447 2007 0.3292679666848599 2008 0.32602650251907495 2009 0.31461925035200183 2010 0.3157709133617782 2011 0.2885290726984263 2012 0.2974836579850629 2013 0.23930296086602404 2014 0.2267490479578237 2015 0.2206472791339269 2016 0.1997772860235651 2017 0.1917422160404612 2018 0.17187833824560597 2019 0.1670724042780718 2020 0.15399336084806395