Year billion cubic meters 1975 1.07 1976 1.236 1977 1.402 1978 1.568 1979 1.734 1980 1.9 1981 1.98 1982 2.06 1983 2.14 1984 2.22 1985 2.3 1986 2.455 1987 2.61 1988 2.765 1989 2.92 1990 3.067 1991 3.0234 1992 2.9798 1993 2.9362 1994 2.8926 1995 2.849 1996 2.8046 1997 2.7602 1998 2.7158 1999 2.6714 2000 2.6 2001 2.809 2002 2.824 2003 2.839 2004 2.854 2005 2.869 2006 2.884 2007 2.899 2008 2.914 2009 3.015 2010 3.116 2011 3.217 2012 3.3188 2013 3.4206 2014 3.5224 2015 3.6242 2016 3.726 2017 3.526 2018 3.78072 2019 3.793 2020 3.864