Year	billion cubic meters
1961	1605.26
1962	1642.8249999999998
1963	1642.8249999999998
1964	1642.8249999999998
1965	1642.8249999999998
1966	1642.8249999999998
1967	1642.8249999999998
1968	1642.8249999999998
1969	1642.8249999999998
1970	1642.8249999999998
1971	1642.8249999999998
1972	1642.8249999999998
1973	1642.8249999999998
1974	1642.8249999999998
1975	1642.8249999999998
1976	1642.8249999999998
1977	1642.8249999999998
1978	1642.8249999999998
1979	1642.8249999999998
1980	1642.8249999999998
1981	1642.8249999999998
1982	1642.8249999999998
1983	1642.8249999999998
1984	1642.8249999999998
1985	1642.8249999999998
1986	1642.8249999999998
1987	1642.8249999999998
1988	1642.8249999999998
1989	1642.8249999999998
1990	1642.8249999999998
1991	1642.8249999999998
1992	1659.1649999999997
1993	1659.1649999999997
1994	1659.1649999999997
1995	1659.1649999999997
1996	1659.1649999999997
1997	1659.1649999999997
1998	1659.1649999999997
1999	1659.1649999999997
2000	1659.1649999999997
2001	1659.1649999999997
2002	1659.1649999999997
2003	1659.1649999999997
2004	1659.1649999999997
2005	1659.1649999999997
2006	1659.1649999999997
2007	1659.1649999999997
2008	1659.1649999999997
2009	1659.1649999999997
2010	1659.1649999999997
2011	1659.1649999999997
2012	1659.1649999999997
2013	1659.1649999999997
2014	1659.1649999999997
2015	1659.1649999999997
2016	1659.1649999999997
2017	1659.1649999999997
2018	1659.1649999999997
2019	1659.1649999999997
2020	1659.1649999999997