Year	billion cubic meters
2000	0.2714
2001	0.29554
2002	0.31968
2003	0.34382
2004	0.36796
2005	0.3921
2006	0.3921
2007	0.3921
2008	0.3921
2009	0.3921
2010	0.3921
2011	0.3921
2012	0.3921
2013	0.3921
2014	0.3921
2015	0.3921
2016	0.3921
2017	0.3921
2018	0.3921
2019	0.3921
2020	0.3921