Year	billion cubic meters
1961	26793.738999999998
1962	26948.413999999997
1963	26948.414
1964	26948.413999999997
1965	26948.413999999997
1966	26948.414
1967	26948.413999999997
1968	26948.414
1969	26948.414
1970	26948.414
1971	26948.413999999997
1972	26948.413999999997
1973	26948.413999999997
1974	26948.413999999997
1975	26948.413999999997
1976	26948.414
1977	26948.414
1978	26948.413999999997
1979	26948.413999999997
1980	26948.414
1981	26948.413999999997
1982	26948.413999999997
1983	26948.414
1984	26948.414
1985	26948.414
1986	26948.414
1987	26948.413999999997
1988	26948.414
1989	26948.413999999997
1990	26948.413999999997
1991	26948.414
1992	31659.622999999996
1993	31784.423
1994	31770.422999999995
1995	31770.423
1996	31769.523
1997	31770.422999999995
1998	31770.422999999995
1999	31770.423
2000	31770.423
2001	31770.422999999995
2002	31770.423
2003	31770.42299999999
2004	31767.422999999995
2005	31767.422999999995
2006	31775.829999999994
2007	31775.829999999998
2008	31775.829999999994
2009	31775.829999999994
2010	31775.829999999994
2011	31775.829999999998
2012	31805.829999999994
2013	31805.829999999998
2014	31805.829999999994
2015	31805.829999999994
2016	31805.829999999994
2017	31805.829999999994
2018	31805.829999999994
2019	31805.829999999994
2020	31805.829999999994