Year	billion cubic meters
1961	351.679
1962	371.579
1963	371.579
1964	371.579
1965	371.579
1966	371.579
1967	371.579
1968	371.579
1969	371.579
1970	371.579
1971	371.579
1972	371.579
1973	371.579
1974	371.579
1975	371.579
1976	371.579
1977	371.579
1978	371.579
1979	371.579
1980	371.579
1981	371.579
1982	371.579
1983	371.579
1984	371.579
1985	371.579
1986	371.579
1987	371.579
1988	371.579
1989	371.579
1990	371.579
1991	371.579
1992	371.57899999999995
1993	371.57899999999995
1994	371.57899999999995
1995	371.57899999999995
1996	371.57899999999995
1997	371.57899999999995
1998	371.57899999999995
1999	371.57899999999995
2000	371.57899999999995
2001	371.57899999999995
2002	371.57899999999995
2003	371.57899999999995
2004	371.57899999999995
2005	371.57899999999995
2006	371.57899999999995
2007	371.57899999999995
2008	371.57899999999995
2009	371.57899999999995
2010	371.57899999999995
2011	371.57899999999995
2012	371.57899999999995
2013	371.57899999999995
2014	371.57899999999995
2015	371.57899999999995
2016	371.57899999999995
2017	371.57899999999995
2018	371.57899999999995
2019	371.57899999999995
2020	371.57899999999995