BEIJING, Nov. 18 -- China's migrant population reached 245 million by the end of 2013, composing more than one sixth of the nation's total population, a government report said Tuesday.

The trend of people moving into big cities has not changed and the average age of the migrant population is rising, according to the report released by the National Health and Family Planning Commission.

By the end of 2012, the migrant population, referring to those who have left their birthplaces to live and work elsewhere, amounted to 236 million. Many of the group are former farmers who go to cities to open small businesses or provide cheap labor in the hope of higher pay and a better life.

Over 62 percent of the migrant couples' children aging between six and fifteen have moved along with their parents, the report said.