The Municipality of Athens has an official population of 664,046 people. The four regional units that make up what is referred to as Greater Athens have a combined population of 2,640,701. They together with the regional unit of Piraeus (Greater Piraeus) make up the dense Athens Urban Area which reaches a total population of 3,090,508 inhabitants (in 2011). According to Eurostat, in 2013 the functional urban area of Athens had 3,828,434 inhabitants, being apparently decreasing compared with the pre-economic crisis date of 2009 (4,164,175)