Year billion cubic meters 1961 3728.961 1962 3728.9610000000007 1963 3728.9610000000007 1964 3728.961 1965 3728.9610000000007 1966 3728.9610000000007 1967 3728.961 1968 3728.9610000000007 1969 3728.9610000000007 1970 3728.9610000000007 1971 3728.961 1972 3728.9610000000007 1973 3728.9610000000007 1974 3728.961 1975 3728.961 1976 3728.961 1977 3728.9610000000007 1978 3728.9610000000007 1979 3728.9610000000007 1980 3728.9610000000007 1981 3728.961 1982 3728.9610000000007 1983 3728.961 1984 3728.961 1985 3728.9610000000007 1986 3728.961 1987 3728.9610000000007 1988 3728.961 1989 3728.961 1990 3728.9610000000007 1991 3728.961 1992 3728.9610000000007 1993 3853.761 1994 3853.761 1995 3853.761 1996 3853.761 1997 3853.761000000001 1998 3853.761 1999 3853.761 2000 3853.761000000001 2001 3853.761000000001 2002 3853.761 2003 3853.761 2004 3853.761 2005 3853.761000000001 2006 3853.761000000001 2007 3853.761 2008 3853.761 2009 3853.761 2010 3853.761 2011 3853.761 2012 3883.761000000001 2013 3883.761 2014 3883.761000000001 2015 3883.761000000001 2016 3883.761000000001 2017 3883.761000000001 2018 3883.761 2019 3883.761 2020 3883.761