The graph below shows the number of complaints made about noise to Environmental Health authorities in the city of Newtown between 1980 and 1996

The line chart depicts the proportions of noise

complaints

which are categorized into four groups and surveyed biannually from 1980 to 1996 in Newton. In general, all of the

cases

had upward trends

while

only

cases

related to the household had a downward tendency. In detail, approximately 500

complaints

of road works were reported from 1980 to 1984. Surprisingly, the number declined to 400 and fairly remained stable in 1988. At the same time, traffic noise had a similar condition which was stable on 200

complaints

after fell steadily. In the following year, both of them rose dramatically and the road works were the most complained source of the noise.

On the other hand

, the number of

complaints

in factories had a gradual increase from 400 to 600,

then

fluctuated slightly until 1996.

While

the other

cases

increased, the domestic or household

cases

dropped significantly in 1996 from 700 to 100.

This

number indicated that the most solved problem handled by health authorities year by year was domestic

cases

.