Year	billion cubic meters
1987	0.81
1988	1.0007615385
1989	1.1915230769
1990	1.3822846154
1991	1.5730461538
1992	1.7638076923
1993	1.9545692308
1994	2.1453307692
1995	2.3360923077
1996	2.5268538462
1997	2.7176153846
1998	2.9083769231
1999	3.0991384615
2000	3.2899
2001	3.2926
2002	3.2953
2003	3.298
2004	3.298
2005	3.298
2006	3.298
2007	3.298
2008	3.298
2009	3.298
2010	3.298
2011	3.298
2012	3.298
2013	3.298
2014	3.298
2015	3.298
2016	3.298
2017	3.298
2018	3.298
2019	3.298
2020	3.298