Year billion cubic meters 1992 2.63 1993 2.206 1994 1.782 1995 1.358 1996 1.3659142857 1997 1.3738285714 1998 1.3817428571 1999 1.3896571429 2000 1.3975714286 2001 1.4054857143 2002 1.4134 2003 1.4975 2004 1.5816 2005 1.6657 2006 1.7498 2007 1.8339 2008 1.604 2009 1.378 2010 1.842 2011 1.874 2012 1.631 2013 1.748 2014 1.72 2015 1.61534264 2016 1.7514 2017 1.7849 2018 1.60854 2019 1.00645 2020 0.8529523