Pie charts - The spending of a school in three different years

[Fouryz]

Here is the link to the chart: https://i0.wp.com/ieltsliz.com/wp-content/uploads/2014/11/school-spending-ielts-chart.png

Here is my answer:
"The pie charts illustrate the expenditure in five major categories of a school in three different years, 1981, 1991 and 2001. At first glance, it is clear that teachers’ salaries was the school’s main expense while the percentage of other spending classifications changed considerably over the years in the question.
In more detail, with the constant noticeable percentage of more than two-fifths to about a half in all three years, teachers’ salaries was the top expenditure of the school. Secondly, expenses on furniture and equipment as well as on resources each made up 15% of the total outlay in 1981. Nevertheless, the proportion of furniture and equipment cost reduced to merely 5% in 1991, then recovered to approximately a quarter in 2001. In contrast, despite accounting for up to one-fifth in 1991, spending on resources only comprised of under one-tenth in 2001.
Finally, the money spent for other workers gradually become less and less significant over the years, with 28%, 22% and 15% respectively in 1981, 1991 and 2001 (Is this sentence too lengthy, can I omit the underlined part). As regards to insurance, the expense made up a very small amount, with under 10% in all three years."

TOEFL listening lectures: A lecture in social science class
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[Luschen]

Hi Fouryz, thanks for posting the link. This is another pretty good report, but this one had a few sentences that were not quite clear to me. I think your transitions sounded very good though. Here are my specific suggestions: