Query: When did a mass migration of the community that  previously held a persuasive authority on the Burmese population start?
Context: Included in this group are the Anglo-Burmese. Once forming a large and influential community, the Anglo-Burmese left the country in steady streams from 1958 onwards, principally to Australia and the UK. It is estimated that 52,000 Anglo-Burmese remain in Myanmar.