In total 11 city regions had over 27 million residents in 2015, over 40% of the total UK population of 65 million. Population projections from 2015 to 2025 show city regions have a percentage growth rate of 7.6% compared to the UK growth rate of 6.7%. Greater London, Bristol, the West Midlands and Edinburgh city regions all have higher projected population growth rates than the UK. Projected population change (principal projections), mid-2015 to mid-2025 Source:
Population dynamics of UK city regions since mid-2011, Office for National Statistics, October 2016