As of October 2012, the official intercensal estimate showed 13.506 million people in Tokyo with 9.214 million living within Tokyo's 23 wards. During the daytime, the population swells by over 2.5 million as workers and students commute from adjacent areas. This effect is even more pronounced in the three central wards of Chiyoda, Chūō, and Minato, whose collective population as of the 2005 National Census was 326,000 at night, but 2.4 million during the day.