The line graph gives information on the changes in the proportion of river water in high quality in Wales, Northern Ireland, England and Scotland between 1990 and 2002.
Overall, while the water quality in Wales and Northern Ireland showed a relative stability trend over the period, the figures for Scotland and England fluctuated throughout the years.
The figures for Wales and Northern Ireland stayed consistent between 1990 and 1998, coming in at almost 95% and 86%, respectively. Following this time, Wales’s water quality declined roughly, with 80% of its rivers having high-quality water by 2002. On the other hand, the Northern Ireland figure showed an upward trend and peaked in 2000 at 95%, remaining constant until the end of the period.
Conversely, in 1990, the quality of river water in England was the lowest, at little over 20%. After that, the rate went up to about 30%, and by the year 2000, it had grown significantly to reach a peak of roughly 60%. The figure decreased to 40% at the end of the term, although having increased. Similar circumstances applied to the data for Scotland, which peaked at almost 70% in 1996 before drastically declining to 30% and then gradually increasing to 50% in 2002.