The three pie charts below show how the changes in annual spending by a particular UK school in 1981 1991 and 2001

The pie charts compare the changes in the expenditure of a British school in three different years (1981, 1991, and 2001).
Overall, teachers' salaries accounted for the highest proportion of total spending, while the school spent the least on insurance in three years surveyed.
In the year 1981, 40% of the school's budget was spent on teachers' salaries, which then rose to 50% but fell back to 45% in 2001. Over 20 years, there was a fourfold increase in the figure for insurance, from 2% to 8%.
Turning to the remaining sectors, salaries for other workers dropped slightly by 7% over the period shown. Meanwhile, despite a sharp decrease of 10% during the first 10 years, expenditure on furniture and equipment rose dramatically to 23% in 2001. By contrast, spending on resources increased marginally from 15% in 1981 to 20% after 10 years but finally ended at a mere 9%.