<P> Until the late 20th century, the market was dominated by eight networks but this gradually reduced due to mergers and the 2002 collapse of one firm, leaving four networks dominating the market in the early 21st century . </P> <P> In the UK in 2011, it was reported that the Big Four audit 99% of the companies in the FTSE 100, and 96% of the companies in the FTSE 250 Index, an index of the leading mid-cap listing companies . Such industry concentration has caused concern and calls for the Competition and Markets Authority to consider breaking up the Big Four . In October 2018, the CMA announced it had launched a detailed study of the Big Four's dominance of the audit sector . </P> <Table> <Tr> <Th> Firm </Th> <Th> Revenues </Th> <Th> Employees </Th> <Th> Revenue per employee </Th> <Th> Fiscal year </Th> <Th> Headquarters </Th> <Th> Source </Th> </Tr> <Tr> <Td> Deloitte </Td> <Td> $43.2 bn </Td> <Td> 286,200 </Td> <Td> $150,943 </Td> <Td> 2018 </Td> <Td> United Kingdom </Td> <Td> </Td> </Tr> <Tr> <Td> PwC </Td> <Td> $41.3 bn </Td> <Td> 250,930 </Td> <Td> $164,588 </Td> <Td> 2018 </Td> <Td> United Kingdom </Td> <Td> </Td> </Tr> <Tr> <Td> EY </Td> <Td> $34.8 bn </Td> <Td> 260,000 </Td> <Td> $133,846 </Td> <Td> 2018 </Td> <Td> United Kingdom </Td> <Td> </Td> </Tr> <Tr> <Td> KPMG </Td> <Td> $26.4 bn </Td> <Td> 197,263 </Td> <Td> $133,830 </Td> <Td> 2017 </Td> <Td> Netherlands </Td> <Td> </Td> </Tr> </Table> <Tr> <Th> Firm </Th> <Th> Revenues </Th> <Th> Employees </Th> <Th> Revenue per employee </Th> <Th> Fiscal year </Th> <Th> Headquarters </Th> <Th> Source </Th> </Tr>

List of top accounting firms in the philippines