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

These three pie charts provide information about the alterations in yearly expenditure by a specific educational institution in the United Kingdom in various years 1981, 1991, and 2001. As is observed in the given diagram, teachers' salaries maintained a leading position in percentage terms,

while

insurance was at the lowest level of annual expenses for the period under review. From the graph, we can see that between 1981 and 2001 other workers' salaries markedly decreased from 28% to 15%, meanwhile, insurance significantly rose from 2% to 8%.

Further

, from 1981 to 1991 furniture and equipment fell considerably by 10 percent, but it jumped by 23%in 2001. At the same time, the share of resources and books went up to 5%,

however

,

at the end

of the period it greatly went down to 9%. It is very noticeable that during these three years, teachers' salaries retained the top rank and fluctuated over the years. At the beginning of the period,

this

indicator was 40%, in 1991 it grew to 50%, and in 2001 it dropped to 45%.