Year billion cubic meters 1999 0.01 2000 0.01 2001 0.01 2002 0.01 2003 0.01 2004 0.01 2005 0.01 2006 0.01 2007 0.01 2008 0.01 2009 0.01 2010 0.01 2011 0.01 2012 0.01 2013 0.01 2014 0.01 2015 0.01 2016 0.01 2017 0.01 2018 0.01 2019 0.01 2020 0.01