The pie charts below show the changes in annual spending by a particular UK school in 1981, 1991 and 2001. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

The charts compare changes in the shares of five different items which comprised the yearly expenditures of a British school between 1981 and 2001.

Overall

, rises can be seen in three items,

while

the remaining experienced decline.

Moreover

, academic staff salaries contributed to the largest proportion of expenses throughout the survey,

whereas

insurance was responsible for the smallest shares. One of the prominent features is wages for teaching officers accounted for the most significant proportion in 1981 at 40% and went up by one-tenth before declining slightly in 2001 to 45%. In comparison, non-academic employees' salaries were responsible for less than one-third of all expenditures in 1981 and experienced a gradual drop of 15% until the end of the survey. The share of furniture and equipment was

initially

as high as that of educational resources in 1981.

However

,

while

the former had a significant decline by 2/3 in 1991 before rising fivefold in 2001, the latter had a moderate rise of 5% in 1991 after which it halved, reaching just below 10% in 2001. The contribution of insurance was relatively the smallest among all expenses,

initially

at 2%, and had risen slightly to 3% by 1991 before rising threefold in 2001.