Year	billion cubic meters
1989	0.0119
1990	0.0118567143
1991	0.0118134286
1992	0.0117701429
1993	0.0117268571
1994	0.0116835714
1995	0.0116402857
1996	0.011597
1997	0.0115537143
1998	0.0115104286
1999	0.0114671429
2000	0.0114238571
2001	0.0113805714
2002	0.0113372857
2003	0.011294
2004	0.011294
2005	0.011294
2006	0.011294
2007	0.011294
2008	0.011294
2009	0.011294
2010	0.011294
2011	0.011294
2012	0.011294
2013	0.011294
2014	0.011294
2015	0.011294
2016	0.011294
2017	0.011294
2018	0.011294
2019	0.011294
2020	0.011294