Year	billion cubic meters
1961	164
1962	164
1963	164
1964	164
1965	164
1966	164
1967	164
1968	164
1969	164
1970	164
1971	164
1972	164
1973	164
1974	164
1975	164
1976	164
1977	164
1978	164
1979	164
1980	164
1981	164
1982	164
1983	164
1984	164
1985	164
1986	164
1987	164
1988	164
1989	164
1990	164
1991	164
1992	164
1993	164
1994	164
1995	164
1996	164
1997	164
1998	164
1999	164
2000	164
2001	164
2002	164
2003	164
2004	164
2005	164
2006	164
2007	164
2008	164
2009	164
2010	164
2011	164
2012	164
2013	164
2014	164
2015	164
2016	164
2017	164
2018	164
2019	164
2020	164