The chart below shows the percentage of river water in UK rivers that is classified as having good chemical quality between 1990 and 2002.

Presented for consideration is a line chart illustrating the percentage of river water which was regarded as having good chemical quality in the UK over a period of 12 years starting from 1990. Units are measured in percentage.

Overall

, as can be seen from the line chart,

initially

Wales took the lead in 1990

then

Northern Ireland surpassed in the most recent data but Scotland showed a rise In 1990,

firstly

about 95% and 85% respectively of Wales and Northern Ireland were generated by UK citizens. For comparison, seven years later Northern Ireland saw an increase of 10%

while

Wales experienced the opposite trend. From that point on, the proportion of river water in England about 43% during the period of 1990., increased modestly to below 70% before dropping sharply accounting for 40% and reaching its lowest level in 1998.

Similarly

, Scotland witnessed a threefold increase from over 20% in 2000, followed by a rapid decrease to 40% two years later approximately 10% lower than the figure of England in 2000.