Year	billion cubic meters
1961	35.2
1962	35.2
1963	35.2
1964	35.2
1965	35.2
1966	35.2
1967	35.2
1968	35.2
1969	35.2
1970	35.2
1971	35.2
1972	35.2
1973	35.2
1974	35.2
1975	35.2
1976	35.2
1977	35.2
1978	35.2
1979	35.2
1980	35.2
1981	35.2
1982	35.2
1983	35.2
1984	35.2
1985	35.2
1986	35.2
1987	35.2
1988	35.2
1989	35.2
1990	35.2
1991	35.2
1992	35.2
1993	35.2
1994	35.2
1995	35.2
1996	35.2
1997	35.2
1998	35.2
1999	35.2
2000	35.2
2001	35.2
2002	35.2
2003	35.2
2004	35.2
2005	35.2
2006	35.2
2007	35.2
2008	35.2
2009	35.2
2010	35.2
2011	35.2
2012	35.2
2013	35.2
2014	35.2
2015	35.2
2016	35.2
2017	35.2
2018	35.2
2019	35.2
2020	35.2