Year	billion cubic meters
1990	0.7976
1991	0.80348
1992	0.80936
1993	0.81524
1994	0.82112
1995	0.827
1996	0.83288
1997	0.83876
1998	0.84464
1999	0.85052
2000	0.8564
2001	0.8848
2002	0.9132
2003	0.9416
2004	0.97
2005	0.9984
2006	1.00212
2007	1.00584
2008	1.00938
2009	1.01328
2010	1.017
2011	0.98836
2012	0.9602
2013	0.9318
2014	0.9034
2015	0.875
2016	0.875
2017	0.875
2018	0.875
2019	0.875
2020	0.875