BEIJING -?Over 2.65 million overseas students have returned to China as of the end of 2016, a survey showed Tuesday.

Of them, 70 percent made their return after the 18th National Congress of the Communist Party of China (CPC) in 2012, according to the survey.

Jointly conducted by the Organization Department of the CPC, the Ministry of Human Resources and Social Security and the National Bureau of Statistics, the survey was the first of its kind since 2010.

As of 2015, the talent pool of China had more than 175 million people, who accounted for 15.5 percent of the human resources in the country.

Professionals in social work saw the biggest boost in the five years, as the number increased to 759,000, up 272 percent from 2010. Rural areas saw a 61.4-percent increase, the survey said.

The human capital investment accounted for 15.8 percent of the country's GDP, which grew by 3.8 percent compared to 2010, and the talent contribution to China's economic growth was also growing, as they contributed to 33.5 percent of growth in 2015, up 6.9 percent from 2010.