Year	billion cubic meters
1961	10066.3765
1962	10070.5421
1963	10070.5421
1964	10070.5421
1965	10070.5421
1966	10070.5421
1967	10070.5421
1968	10070.5421
1969	10070.5421
1970	10070.5421
1971	10070.5421
1972	10070.5421
1973	10070.5421
1974	10070.5421
1975	10070.5421
1976	10070.5421
1977	10070.5421
1978	10070.5421
1979	10070.5421
1980	10070.5421
1981	10070.5421
1982	10070.5421
1983	10070.5421
1984	10070.5421
1985	10070.5421
1986	10070.5421
1987	10070.5421
1988	10070.5421
1989	10070.5421
1990	10070.5421
1991	10070.5421
1992	10172.0221
1993	10197.772099999998
1994	10197.772099999998
1995	10197.772099999998
1996	10197.772099999998
1997	10197.772099999998
1998	10197.772099999998
1999	10197.772099999998
2000	10197.772099999998
2001	10197.772099999998
2002	10197.772099999998
2003	10197.772099999998
2004	10197.772099999998
2005	10197.772099999998
2006	10197.772099999998
2007	10197.772099999998
2008	10197.772099999998
2009	10197.772099999998
2010	10197.772099999998
2011	10197.772099999998
2012	10197.772099999998
2013	10197.772099999998
2014	10197.772099999998
2015	10197.772099999998
2016	10197.772099999998
2017	10197.772099999998
2018	10197.772099999998
2019	10197.772099999998
2020	10197.772099999998