Discuss the usefulness and limitations of financial ratios in evaluating the performance and management of companies

Discuss the usefulness and limitations of financial ratios in evaluating the performance and management of companies
Ratio analysis is considered to be one of the most important tools in financial performance evaluation. Some companies are now voluntarily disclosing ratios in their annual reports.
Required:
Write an essay on the following topic:
Discuss the usefulness and limitations of financial ratios in evaluating the performance and management of companies.
Support your discussion by giving examples of ratios derived from the annual report of the following company:EasyJet plc Annual Report and Accounts 2013