Year	billion cubic meters
1961	12.5
1962	12.5
1963	12.5
1964	12.5
1965	12.5
1966	12.5
1967	12.5
1968	12.5
1969	12.5
1970	12.5
1971	12.5
1972	12.5
1973	12.5
1974	12.5
1975	12.5
1976	12.5
1977	12.5
1978	12.5
1979	12.5
1980	12.5
1981	12.5
1982	12.5
1983	12.5
1984	12.5
1985	12.5
1986	12.5
1987	12.5
1988	12.5
1989	12.5
1990	12.5
1991	12.5
1992	12.5
1993	12.5
1994	12.5
1995	12.5
1996	12.5
1997	12.5
1998	12.5
1999	12.5
2000	12.5
2001	12.5
2002	12.5
2003	12.5
2004	12.5
2005	12.5
2006	12.5
2007	12.5
2008	12.5
2009	12.5
2010	12.5
2011	12.5
2012	12.5
2013	12.5
2014	12.5
2015	12.5
2016	12.5
2017	12.5
2018	12.5
2019	12.5
2020	12.5