Year	Rhine, Lobith	Danube, Vienna	Meuse, Eijsden	Lake Saimaa, Finland	Lake Võrtsjärv, Estonia
1901		9
1902		8.5
1903		9.1
1904		9.4
1905		9
1906		9.4
1907		9
1908		8.9
1909		8.7
1910		9.1	11.73
1911	11.5	9.7	12.6
1912	10.7	8.6	12
1913	11.3	9.2	12.2
1914	10.8	8.9	12
1915	11.1	9.1	11.5
1916	11.2	9.6	11.5
1917	10.7	9	11.3
1918	11.1	9.4	11.6
1919	10.5	8.8	11.2
1920	11.3	9.5	12.1
1921		8.8	12.8
1922	10.6	8.8	11.2
1923	10.6	9.4	11.8
1924	9.9	8.5	11.4	17.4
1925	11.3	8.8	11.7	19.1
1926	11.6	9.1	12.2	17.7
1927	11.2	9.4	11.7	19.2
1928	11.4	9.4	12.4	16
1929	11	8.8	11.6	16.4
1930	11.9	9.7	12.4	18.1
1931	10.9	8.9	12	18
1932	11.3	9.5	12.3	19
1933	10.9	9	12.5	16.6
1934	12.1	10.1	13.6	19.3
1935	11.7	9.2	12.8	16.5
1936	11.7	9	12.7	17.3
1937	12.1	9.3	13	18.4
1938	12	9.6	13.1	19
1939	11.6	9.7	12.6	19.2
1940	10.6	8.7	11.3	16.9
1941	10.8		11.6	17.4
1942	11.4		11.8	16.5
1943	12.5	9.8	12.8	16.9
1944		9.2	11.9	18.2
1945			11.9	18.5
1946	11.6	9.9	12.6	18.7
1947	12	9.9	13.2	18.8	8.3
1948	11.8	9.7	13.3	17.1	8.3
1949		9.8	13.8	16.6	8.5
1950	12.1	10.2	12.8	18.7	8.2
1951	11.9	10	12.6	18.8	7.7
1952	11.7	9.4	12.5	17.8	7.4
1953	12.3	10	13.2	17.8	8.2
1954	11.5	9.1	11.7	18	8.3
1955	11.6	9.1	12.3	19.9	7.7
1956	11.1	9	11.4	16.4	7.4
1957	12.4	9.8	12.5	18.7	8.1
1958	12.1	9.7	12.2	17.6	7.7
1959	12.9	10	14	20.3	8.3
1960	12.6	9.9	13	19	8.6
1961	12.8	10.4	13.3	17.8	8.4
1962	11.9	9	12.2	16.4	7.4
1963	11.6	9.5	12.3	19.2	8.4
1964	12.8	9.7	13.8	17	8.2
1965	11.4	8.7	12.1	16.2	8.1
1966	12.5	9.7	12.8	18	8.1
1967	12.8	9.8	13.7	19.4	8.7
1968	12.2	9.9	13.1	18.2	8.4
1969	12.4	10	13.3	19.5	8.1
1970	11.9	9	13.1	18.9	8.0
1971	13.2	10.4	14.1	18.6	8.3
1972	12.7	9.8	13.5	20	9.1
1973	12.7	9.7	14.1	19	8.2
1974	13	10.1	14.1	17.8	8.4
1975	13.1	9.7	14.9	19.7	8.6
1976	13.9	10.1	15.3	17.6	7.2
1977	13.1	10	14.4	18.4	7.8
1978	12.3	9.5	14.1	17.6	7.6
1979	12.7	9.4	13.6	18.3	7.9
1980	12.3	8.8	13.5	19.7	8.0
1981	12.6	9.5	13.6	18.1	8.0
1982	13.4	10.1	14.3	18.6	7.8
1983	13.2	10.4	14.3	18.9	8.4
1984	12.8	9.7	13.9	18.7	8.6
1985	12.6	9.7	13.8	18.8	8.1
1986	12.6	10.2	13.5	19	8.5
1987	12.3	9.5	13.6	15	7.1
1988	13.4	10.4	14.8	17.9	8.6
1989	14.6	10.5	15.3	18.6	9.1
1990	14.4	10.9	16.2	19	8.4
1991	13.7	10.1	14.6	20.2	8.6
1992	14.1	10.8	14.7	17.7	8.3
1993	14.2	10.2	14.5	18	8.0
1994	14.8	11.3	15.2	19.9	8.3
1995	13.6	10.2	14.9	18.9	8.8
1996	13	9.5	13.7	19.8	8.2
1997	14	10	14.6	20.7	8.2
1998	13.4	10.7	13.7	18.6	8.8
1999	13.7		14.6	19.4	9.1
2000	14.4		14.4	19.5	9.1
2001	13.8		13.9		8.9
2002	13.9		14.1	22.2	8.8
2003	14.4		14.9	19.8	8.6
2004	13.8		14.6	19.9	8.3
2005	13.9		14.9	19.3	8.3
2006	14.2		14.5	20.2	9.0
2007	14.4		14.5	20.7	8.5
2008	14.1		13.7	18.4	8.3
2009	13.8		14.1	19.9	8.1
2010	13.4		13.7	21.3	8.6
2011	14.6		14.7	20.2	9.1
2012	13.8		13.6	18.6	8.2
2013	13.2		13.4	20.1	8.9
2014				20.9	9.6