- Ammonium Legend

Note: Concentrations are expressed as annual mean concentrations. Only complete series after inter/extrapolation are included (see indicator specification). Two time series are depicted – the longer time series with less stations and the shorter time series with more stations.
The number of river monitoring stations included per country is given in parenthesis.
1992-2015: Europe (851), Albania (7), Austria (46), Belgium (28), Bulgaria (57), Estonia (48), Finland (80), Former Yugoslav Republic of Macedonia (9), France (162), Germany (133), Ireland (4), Latvia (17), Lithuania (24), Luxembourg (3), Norway (43), Poland (3), Slovenia (10), Spain (45), Sweden (119), United Kingdom (13).
2000-2015: Europe (1340), Albania (11), Austria (48), Belgium (35), Bosnia and Herzegovina (13), Bulgaria (85), Croatia (41), Estonia (51), Finland (93), Former Yugoslav Republic of Macedonia (19), France (240), Germany (136), Iceland (1), Ireland (35), Italy (58), Latvia (21), Lithuania (24), Luxembourg (3), Norway (43), Poland (9), Romania (116), Serbia (31), Slovenia (10), Spain (82), Sweden (122), United Kingdom (13).