According to the Outline of the Plan for the Reform and Development of the Pearl River Delta (PRD) for 2008 -2020, formulated by the National Development and Reform Commission, cities in the PRD are progressively converging into one urban cluster, forming the most densely populated urban corridor in China. The nine prefectures in the region were home to 56.15 million people at the end of 2010, according to the Guangdong Statistic Book 2010. Given that Guangzhou alone expects to have 20 million people by 2020, it is entirely possible the total population of the PRD could double by that time.