Year billion cubic meters 1961 28702.663 1962 28861.188 1963 28861.187999999995 1964 28861.188000000002 1965 28861.188 1966 28861.187999999995 1967 28861.187999999995 1968 28861.188 1969 28861.187999999995 1970 28861.187999999995 1971 28861.188 1972 28861.187999999995 1973 28861.187999999995 1974 28861.188 1975 28861.188 1976 28861.188 1977 28861.187999999995 1978 28861.187999999995 1979 28861.187999999995 1980 28861.188000000002 1981 28861.187999999995 1982 28861.187999999995 1983 28861.188 1984 28861.187999999995 1985 28861.188000000002 1986 28861.187999999995 1987 28861.187999999995 1988 28861.188 1989 28861.188 1990 28861.188 1991 28861.188 1992 33610.09699999999 1993 33734.897 1994 33720.89699999998 1995 33720.89699999998 1996 33719.996999999996 1997 33720.89699999999 1998 33720.89699999998 1999 33720.89699999998 2000 33720.89699999998 2001 33720.89699999998 2002 33720.89699999998 2003 33720.89699999998 2004 33717.89699999998 2005 33717.89699999999 2006 33726.30399999998 2007 33726.30399999998 2008 33726.30399999998 2009 33726.30399999998 2010 33726.30399999998 2011 33726.30399999998 2012 33756.30399999998 2013 33756.30399999999 2014 33756.30399999998 2015 33756.30399999998 2016 33756.30399999998 2017 33756.303999999975 2018 33756.30399999999 2019 33756.30399999998 2020 33756.30399999999