Year billion cubic meters 1991 1.197 1992 1.2106313131 1993 1.2242626263 1994 1.2378939394 1995 1.2175252525 1996 1.2311565657 1997 1.2447878788 1998 1.2584191919 1999 1.2720505051 2000 1.3 2001 1.2710909091 2002 1.2565 2003 1.186 2004 1.2308 2005 1.2756 2006 1.3204 2007 1.3652 2008 1.41 2009 1.4548 2010 1.4996 2011 1.5444 2012 1.5892 2013 1.634 2014 1.634 2015 1.634 2016 1.634 2017 1.634 2018 1.634 2019 1.634 2020 1.634