Year	cubic meters
1961	4255.645113242716
1962	4225.0459612730065
1963	4208.029473924336
1964	4205.696172761145
1965	4222.88146093918
1966	4254.847446923577
1967	4281.92172647084
1968	4300.272161961829
1969	4339.036311453742
1970	4377.662814208188
1971	4396.237006227385
1972	4403.0251099887255
1973	4401.663365419143
1974	4340.691757768838
1975	4178.822825610026
1976	4061.647254486784
1977	4018.7506444542564
1978	3975.6231527737823
1979	3933.232345867751
1980	3890.926278005454
1981	3857.334650782298
1982	3833.8254586390267
1983	3816.07904907327
1984	3801.432379720679
1985	3791.0481978903213
1986	3787.601664710736
1987	3788.622388106278
1988	3792.562784379831
1989	3798.1009495252374
1990	3806.3878801404517
1991	3815.1710275912164
1992	3818.138448513508
1993	3813.471086613462
1994	3803.2232316888562
1995	3790.0790889766945
1996	3775.855293326822
1997	3759.03516250952
1998	3740.0853290625496
1999	3718.989984955707
2000	3692.942340147589
2001	3666.9901981352004
2002	3646.962162095759
2003	3633.296716714054
2004	3624.618830791442
2005	3617.9002278325065
2006	3611.381859154587
2007	3604.299511977846
2008	3599.1061714536513
2009	3595.6767475249203
2010	3594.026349887923
2011	3599.3165087387615
2012	3613.93854250239
2013	3633.826912217739
2014	3653.473078037608
2015	3668.634985879617
2016	3680.2262990520903
2017	3689.2129355455663
2018	3695.1242446631227
2019	3694.247366609234
2020	3690.366230973613