Year billion cubic meters 2000 8.5556 2001 8.57604 2002 8.59648 2003 8.61692 2004 8.63736 2005 8.6578 2006 8.6578 2007 8.6578 2008 8.6578 2009 8.6578 2010 8.6578 2011 8.6578 2012 8.6578 2013 8.6578 2014 8.6578 2015 8.6578 2016 8.6578 2017 8.6578 2018 8.6578 2019 8.6578 2020 8.6578