Year	billion cubic meters
1984	16.303
1985	16.1196625
1986	15.936325
1987	15.7529875
1988	15.56965
1989	15.3863125
1990	15.202975
1991	15.0196375
1992	14.8363
1993	14.6529625
1994	14.469625
1995	14.2862875
1996	14.10295
1997	13.9196125
1998	13.736275
1999	13.5529375
2000	13.3696
2001	13.38718
2002	13.40476
2003	13.42234
2004	13.43992
2005	13.4575
2006	13.4575
2007	13.4575
2008	13.4575
2009	13.4575
2010	13.4575
2011	13.4575
2012	13.4575
2013	13.4575
2014	13.4575
2015	13.4575
2016	13.4575
2017	13.4575
2018	13.4575
2019	13.4575
2020	13.4575