Year kg per PPP $ of GDP 1990 0.5157437680262902 1991 0.4425742627500587 1992 0.39790775331427614 1993 0.38481819361287734 1994 0.38942894697175884 1995 0.37285041169076255 1996 0.3859334035035797 1997 0.40355046524631705 1998 0.38848531160843464 1999 0.4019852681247599 2000 0.34690411715858166 2001 0.3158468345775555 2002 0.30568140028287544 2003 0.29253364607726234 2004 0.2924457718000921 2005 0.2727738308404301 2006 0.22317345590847465 2007 0.2319685104258698 2008 0.24656553814542018 2009 0.2412233106414006 2010 0.22656428579609422 2011 0.21902045872088788 2012 0.20948202691089932 2013 0.21136938862099128 2014 0.19002204628625555 2015 0.20286181250782978 2016 0.2036211088429458 2017 0.19325454612078216 2018 0.18109684951254085 2019 0.1869384763911164 2020 0.1727435480860018