Year	billion cubic meters
1961	13680.765
1962	13713.554999999998
1963	13713.554999999998
1964	13713.554999999998
1965	13713.554999999998
1966	13713.554999999998
1967	13713.554999999998
1968	13713.554999999998
1969	13713.554999999998
1970	13713.554999999998
1971	13713.555
1972	13713.554999999998
1973	13713.554999999998
1974	13713.554999999998
1975	13713.555
1976	13713.555000000002
1977	13713.555000000002
1978	13713.554999999998
1979	13713.554999999998
1980	13713.554999999998
1981	13713.554999999998
1982	13713.554999999998
1983	13713.554999999998
1984	13713.554999999998
1985	13713.554999999998
1986	13713.554999999998
1987	13713.554999999998
1988	13713.555000000002
1989	13713.554999999998
1990	13713.554999999998
1991	13713.555000000002
1992	18248.608999999993
1993	18261.208999999995
1994	18261.208999999995
1995	18261.20899999999
1996	18260.308999999994
1997	18261.20899999999
1998	18261.208999999995
1999	18261.20899999999
2000	18261.20899999999
2001	18261.208999999988
2002	18261.20899999999
2003	18261.20899999999
2004	18261.208999999988
2005	18261.20899999999
2006	18269.61599999999
2007	18269.615999999995
2008	18269.61599999999
2009	18269.615999999987
2010	18269.61599999999
2011	18269.615999999995
2012	18269.61599999999
2013	18269.61599999999
2014	18269.61599999999
2015	18269.61599999999
2016	18269.61599999999
2017	18269.61599999999
2018	18269.615999999987
2019	18269.615999999987
2020	18269.615999999995