Describing trends and graphs with prepositions
There has been an increase of the number of people aged over thirty. [incorrect]
Between 1990 and 2000, there was a drop 15%. [incorrect]
Between 1990 and 2000, there was a drop of 15%. [correct]
We use a noun describing a specific trend or change + in + a word phrase describing the thing which has changed:
* a(n) cut / decline / decrease / drop / fall / increase / reduction / rise, etc. in something
There have been dramatic cuts in the level of spending on the elderly.
The chart shows a decline in the bird pouplation.
* a(n) change / growth / improvement / trend / variation, etc. in something
There have been significant improvements in health care.
We have seen massive changes in people's lifestyles.
We use a noun describing a change or the result of a change + of + a number showing the size of the change:
* a(n) decrease / drop / fall / increase / reduction / rise, etc. of + number
The statistics show a reduction of 20% in energy costs as a result of the government's new measures.
The radio station experienced a fall of 36,000 listeners to a total audience of 2.1 million.
* a high / low / maximum / total / peak, etc. + of + number
Demand reached a peak of 45,000 in early March.