the three pie charts show the changes in annual spending by a particular UK school in 1981, 1999 and 2001.

The charts compare the changes in the shares of five various items which comprised the yearly expenses by a British school between 1981 and 2001. To begin, it is evident from the chart that academic staff salaries contributed the highest share throughout the period, followed by other non-academic wages, whereas, the figure for insurance remained the smallest over the period. Wages paid to the teaching staff accounted for the most significant proportion of expenditure in 1981 at 40%. Moreover, the salaries for the teachers experienced a surge in 1991 and contributed to half of the overall expenditures, whereas, the wages decreased by 5% in 2001. In comparison, the salaries of the other workers were responsible for less than a third of all the expenses in 1981, however, it was reduced by 6% in 1991. Furthermore, it continued to decrease over time and reached a proportion of 15% by 2001, which was almost half the share in 1981. The share of furniture and expenditure remained the same as that of educational resources at 15%. Although, the former experienced a massive decrease in 1991, however, it was considered as a third most popular share. In addition to, it became the second most significant figure in 2001 with a proportion of 23%, almost near to a third of all expenses. While the latter did not have many contributions in years, 1991 and 2001, moreover, it was quite similar to that of insurance share. In contrast, insurance was considered the least significant share in all these 20 years. It had only 2% share in 1981 and 3% in 1999. However, this share was increased by fivefolds in the year 2001.