Total ammonium concentrations in rivers between 1992 and 2006 in different regions of Europe

Northern Europe: Finland (52), Norway (10), Sweden (79). Western Europe: Austria (92), Belgium (8), Denmark (27), France (97), Germany (99), Luxembourg (3), United Kingdom (14). Eastern Europe: Estonia (48), Hungary (86), Latvia (39), Lithuania (24), Poland (79), Slovenia (14). Southern Europe: Greece (13), Italy (66), Spain (313). Southeastern Europe: Albania (18); Bulgaria (104), FYR of Macedonia (18), Romania (104). Concentrations by regions are expressed as the station weighted mean of the annual mean concentrations by countries. Consistent time series trends between 1992 and 2006 (Northern, Western and Eastern Europe), between 2000 and 2006 (Southern Europe) and between 2001 and 2006 (Southeastern Europe) have been calculated using only stations that have recorded concentrations for each year included in the time series with an exception to countries having one year missing concentrations: Luxembourg (LU) (2003), Albania (AL), the United Kingdom (GB), Italy (IT) and Latvia (LV) (all 2006) and countries having two years missing concentrations: Denmark (DK) and Greece (GR) (2005, 2006).