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

The line graphs demonstrate the amount of good chemicals in river water quality in the UK from 1990 to 2002. The units are measured in proportion.

Overall

it can be seen that

Wales

had the highest percentage

whereas

Scotland had the lowest rate. It

also

is observed

Wales

and Northern Ireland were both higher in the period of 12 years and contrast with England and Scotland which were still lower than others from 1990 to 2002.

To begin

with

Wales

, from 1990 to 1998 the amount remained stable at 95% and decreased to 80%

at the end

of the period. At the same time as

Wales

, Northern Ireland

also

stayed constant at 88% from 1990 to 1998 which rose to 95%

at the end

. Turning to the other details, in 1990, England's quality started at 45% went up gradually to nearly 70% in 1996 and

then

significantly dropped down to 30% in 1998.

After

this

point, the trend jumped to 57% in 2002. A similar trend was recorded in the proportion in Scotland which significantly went up by 60% in 2000 before it declined to 40%

at the end

of the period.