Year	billion cubic meters
1975	10.7
1976	11.9842583333
1977	13.2685166667
1978	14.552775
1979	15.8370333333
1980	17.1212916667
1981	18.40555
1982	19.6898083333
1983	20.9740666667
1984	22.258325
1985	23.5425833333
1986	24.8268416667
1987	26.1111
1988	25.5811818182
1989	25.0512636364
1990	24.5213454545
1991	23.9904734266
1992	23.4603167832
1993	22.9301601399
1994	22.4000034965
1995	21.8698468531
1996	21.3396902098
1997	20.8095335664
1998	20.282
1999	20.282
2000	20.282
2001	20.282
2002	20.282
2003	20.282
2004	20.282
2005	20.282
2006	20.282
2007	20.282
2008	20.282
2009	20.282
2010	20.282
2011	20.282
2012	20.282
2013	20.282
2014	20.282
2015	20.282
2016	20.282
2017	20.282
2018	20.282
2019	20.282
2020	20.282