Year billion cubic meters 1992 20.2852 1993 21.3666285714 1994 22.4480571429 1995 23.5294857143 1996 24.6109142857 1997 25.6923428571 1998 26.7737714286 1999 27.8552 2000 28.9366285714 2001 30.0130821429 2002 31.0895357143 2003 32.1307142857 2004 33.2071428571 2005 34.2835714286 2006 35.36 2007 35.368 2008 35.368 2009 35.368 2010 35.368 2011 35.368 2012 35.368 2013 35.368 2014 35.368 2015 35.368 2016 35.368 2017 35.368 2018 35.368 2019 35.368 2020 35.368