BEIJING, April 20 -- China's mainland population has increased to 1.373 billion by Nov. 1, 2015, 33.77 million more than in 2010, when the sixth national census was conducted, the National Bureau of Statistics (NBS) said Wednesday.

According to the report of a sample survey conducted by the NBS, the annual average growth rate rose to 0.5 percent over the past five years (2010-2015), lower than the 0.57-percent growth rate during the 2000-2010 period.

Males accounted for 51.22 percent of the total mainland population, while females made up 48.78 percent, the report said. But the male-to-female ratio was 105.02, lower than the 2010 ratio of 105.2 .

The mainland population living in urban areas totaled 767.5 million, or 55.88 percent of the total, up by 6.2 percentage points from the 2010 figure, while the population categorized as rural fell to 605.99 million.

The sample survey covers 21.31 million people, accounting for 1.55 percent of the total population, the NBS said.