Year	billion cubic meters
1987	13.841479803999997
1988	15.1659661675
1989	16.019361128299998
1990	16.8675253201
1991	17.6399961786
1992	18.427547036699995
1993	19.3487023396
1994	20.2698576424
1995	21.179274666700007
1996	22.0887301526
1997	22.9528453822
1998	23.904109329799997
1999	24.7825185764
2000	25.6592309904
2001	26.6167123787
2002	27.346491981400007
2003	27.760668685499997
2004	28.174845389399994
2005	28.6570220935
2006	28.9418827644
2007	29.2050147801
2008	29.469482154699996
2009	29.734055248799997
2010	29.9986283429
2011	30.086001437
2012	30.1758967535
2013	30.2550087365
2014	30.3353207196
2015	30.664199369299997
2016	30.741378019
2017	30.6147878277
2018	32.040511
2019	32.2281078
2020	32.2281078