Year	billion cubic meters
1961	5.23
1962	5.23
1963	5.23
1964	5.23
1965	5.23
1966	5.23
1967	5.23
1968	5.23
1969	5.23
1970	5.23
1971	5.23
1972	5.23
1973	5.23
1974	5.23
1975	5.23
1976	5.23
1977	5.23
1978	5.23
1979	5.23
1980	5.23
1981	5.23
1982	5.23
1983	5.23
1984	5.23
1985	5.23
1986	5.23
1987	5.23
1988	5.23
1989	5.23
1990	5.23
1991	5.23
1992	5.23
1993	5.23
1994	5.23
1995	5.23
1996	5.23
1997	5.23
1998	5.23
1999	5.23
2000	5.23
2001	5.23
2002	5.23
2003	5.23
2004	5.23
2005	5.23
2006	5.23
2007	5.23
2008	5.23
2009	5.23
2010	5.23
2011	5.23
2012	5.23
2013	5.23
2014	5.23
2015	5.23
2016	5.23
2017	5.23
2018	5.23
2019	5.23
2020	5.23