Year	billion cubic meters
1961	8.5
1962	8.5
1963	8.5
1964	8.5
1965	8.5
1966	8.5
1967	8.5
1968	8.5
1969	8.5
1970	8.5
1971	8.5
1972	8.5
1973	8.5
1974	8.5
1975	8.5
1976	8.5
1977	8.5
1978	8.5
1979	8.5
1980	8.5
1981	8.5
1982	8.5
1983	8.5
1984	8.5
1985	8.5
1986	8.5
1987	8.5
1988	8.5
1989	8.5
1990	8.5
1991	8.5
1992	8.5
1993	8.5
1994	8.5
1995	8.5
1996	8.5
1997	8.5
1998	8.5
1999	8.5
2000	8.5
2001	8.5
2002	8.5
2003	8.5
2004	8.5
2005	8.5
2006	8.5
2007	8.5
2008	8.5
2009	8.5
2010	8.5
2011	8.5
2012	8.5
2013	8.5
2014	8.5
2015	8.5
2016	8.5
2017	8.5
2018	8.5
2019	8.5
2020	8.5