Year kg per PPP $ of GDP 1990 0.6353140273095625 1991 0.5955004827572838 1992 0.6207805748918511 1993 0.5939195050786011 1994 0.5898460182738586 1995 0.5695289830159518 1996 0.5584955378790242 1997 0.5508086358148425 1998 0.5376770630339215 1999 0.5133125351026037 2000 0.5353830018528296 2001 0.49685563621874435 2002 0.4802216892504007 2003 0.4637991259168379 2004 0.44656186447776086 2005 0.4281244783625414 2006 0.38998446092616146 2007 0.3670688803889322 2008 0.31865799637965353 2009 0.31144192325749076 2010 0.2939270212778079 2011 0.2880782379119009 2012 0.32648679794292534 2013 0.3034159038844859 2014 0.3178350773858662 2015 0.2957073077671447 2016 0.2825172311095019 2017 0.27441809854614746 2018 0.2611931105972784 2019 0.23003985052410925 2020 0.20151863486093718