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

The pie charts display the proportion of various costs contributing in England in 1981, 1991, and 2001.
From an overall perspective, t can be observed that teacher's wage has the highest percentage in investigated yeas. In contrast, the insurance sector is the smallest part of schools spending.
Pie charts illustrate that the tutor's salaries with 40% have the highest percentage in 1981, after 10 years with 10% increment the portion of teacher's wages become 50%, but t drops to 45% in 2001. The equipment accounts for 15% of schools spending, which is matched by resources in 1981. The schools spend more money on resources (20%) in 1991, however, in 2001, the equipment percentage become 14% higher than resources.
Insurance has the smallest section in all years, even though its percentage increase from 2% to 8% over the 20 years. The figure shows that the other worker's salaries witness a vice versa trend and decrease about 13% in these years.
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