Official forecasts predict the country's population will soar to 70 million by 2031 largely as a result of immigration and higher birth rates among recently arrived families. The biggest change last year was a sharp drop in the number of Britons moving abroad with 171,000 going overseas, compared with 207,000 the year before. The number of people migrating out of the UK was down from 400,000 in 2006 to 340,000 last year. This pushed up the net immigration figure because the number of incomers fell only slightly from 591,000 in 2006 to last year's 577,000.