big, considerable, dramatic, enormous, exponential, huge, large, major, marked, massive, significant, substantial, vast | moderate, modest, small | apparent | rapid, sharp | gradual, steady | fivefold, tenfold, etc. | 10%, etc. | net, overall | across-the-board
The pay rise represented an across-the-board increase of between 9% for the highest paid and 32% for the lowest paid worker.

annual, monthly, etc. | dividend, fare, pay, price, rent, salary, tax, temperature, wage

experience, see, show
Many parts of the country have experienced an increase in unemployment. | This year saw an increase in the number of job applicants. | Profits show a steady increase.

enjoy
The country is enjoying the biggest increase in business confidence for years.

achieve
We achieved a small increase in profits of £3,257.

bring (about), cause, lead to, result in
Intensive farming has brought about an increase in outbreaks of food poisoning. | The war resulted in a massive increase in government spending.

reflect, represent | entail, involve, mean
The measures to improve the health service will involve an increase in government spending.

announce, report
The company reported a 9.5% increase in third quarter losses.

occur

on the ~
Burglaries in the area are on the increase.

~ in
There has been an increase in demand for two-bedroom flats.

~ on/over
The figures show a sharp increase on last year''s turnover.

~ to
a dividend increase to 11.4 pence

a rate of increase

considerably, dramatically, enormously, greatly, significantly, substantially | slightly | gradually | rapidly, sharply, steeply | steadily | twofold, threefold, etc.
Sales increased almost fourfold in this period.

be expected to, be likely to
Demand is expected to increase over the next decade.

by
The budget has increased by more than a third in the last year.

from, in
to increase in amount/number/price/size

to
Last month the reward was increased from £20,000 to £40,000.

with
Disability increases with age.