Year kg per 2021 PPP $ of GDP 1990 0.6671189784657491 1991 0.6563374055279007 1992 0.6226706734119382 1993 0.6144705103750457 1994 0.5846071536105095 1995 0.5942456597918112 1996 0.5502071718315522 1997 0.5315748504990315 1998 0.5384038742864619 1999 0.5032850000090483 2000 0.49477013914873824 2001 0.4901536910799088 2002 0.48656104367147646 2003 0.513923330817831 2004 0.538921475308499 2005 0.5531608116352263 2006 0.5486620535003618 2007 0.5307771909714879 2008 0.5053542233459991 2009 0.4995496382979088 2010 0.4994262842578489 2011 0.5029198560262022 2012 0.4812131161101404 2013 0.46796177631372154 2014 0.44313624675000973 2015 0.41168610214451695 2016 0.3882306763211805 2017 0.3744989658406772 2018 0.370329086278208 2019 0.3596046912255747 2020 0.36052688488518403