As of October 2007 about 8.7 million were living in Tokyo's 23 special wards. The number of people in Tokyo increases to over 15 million during the day. About 2.5 million workers and students enter the city everyday. The three central wards of Chiyoda, Chūō, and Minato increase the most. As of 2005, the regular population in those three areas was only 326,000 at night, but there are 2.4 million in those areas during the day.