Year	billion cubic meters
1961	0.682
1962	0.682
1963	0.682
1964	0.682
1965	0.682
1966	0.682
1967	0.682
1968	0.682
1969	0.682
1970	0.682
1971	0.682
1972	0.682
1973	0.682
1974	0.682
1975	0.682
1976	0.682
1977	0.682
1978	0.682
1979	0.682
1980	0.682
1981	0.682
1982	0.682
1983	0.682
1984	0.682
1985	0.682
1986	0.682
1987	0.682
1988	0.682
1989	0.682
1990	0.682
1991	0.682
1992	0.682
1993	0.682
1994	0.682
1995	0.682
1996	0.682
1997	0.682
1998	0.682
1999	0.682
2000	0.682
2001	0.682
2002	0.682
2003	0.682
2004	0.682
2005	0.682
2006	0.682
2007	0.682
2008	0.682
2009	0.682
2010	0.682
2011	0.682
2012	0.682
2013	0.682
2014	0.682
2015	0.682
2016	0.682
2017	0.682
2018	0.682
2019	0.682
2020	0.682