Year	billion cubic meters
1961	20.7
1962	20.7
1963	20.7
1964	20.7
1965	20.7
1966	20.7
1967	20.7
1968	20.7
1969	20.7
1970	20.7
1971	20.7
1972	20.7
1973	20.7
1974	20.7
1975	20.7
1976	20.7
1977	20.7
1978	20.7
1979	20.7
1980	20.7
1981	20.7
1982	20.7
1983	20.7
1984	20.7
1985	20.7
1986	20.7
1987	20.7
1988	20.7
1989	20.7
1990	20.7
1991	20.7
1992	20.7
1993	20.7
1994	20.7
1995	20.7
1996	20.7
1997	20.7
1998	20.7
1999	20.7
2000	20.7
2001	20.7
2002	20.7
2003	20.7
2004	20.7
2005	20.7
2006	20.7
2007	20.7
2008	20.7
2009	20.7
2010	20.7
2011	20.7
2012	20.7
2013	20.7
2014	20.7
2015	20.7
2016	20.7
2017	20.7
2018	20.7
2019	20.7
2020	20.7