An Institute for Government chart showing the progress of mayoral devolution in England between 2013 and 2025. Starting with a limited amount of land but high level of population and economic value in 2014, with mayoral devolution in London all categories increased up to 2017, with incremental step sup to 2023. There has been a more marked increase in the share of land covered by devolution since and this is expected to rise by 2026 with almost 80% of economic output, 70% of the population and almost 60% of the land covered by mayoral devolution.