SHANGHAI - A flood of migrant workers into Shanghai has made the city the most densely populated in the country, according to the latest census.

Over the last decade, the city has jumped from 2,588 people per sq km to 3,631 per sq km, an average annual growth of 3.4 percent.

"The major reason for the population density growth was that more migrant workers choose to find jobs and then settle down in Shanghai instead of returning to their hometowns," said Zhou Haiwang, deputy director of the Institute of Population and Development Studies, Shanghai Academy of Social Sciences.

According to a report released by the Shanghai Bureau of Statistics on Friday, among a population of more than 23 million in Shanghai last year, nearly nine million were migrant workers, almost triple compared to the last national census 10 years ago.

Migrant workers from neighboring Anhui province contributed the most to the city's population growth.

"I've got many relatives and friends trying to find jobs and stay in Shanghai, as we think living in the modern city definitely provides a better future for us and the next generation," said Qiao Meng, a migrant worker from Anhui who works and lives in Songjiang district, a suburb of Shanghai.

With more people moving to suburban areas including Baoshan, Jiading and Jinshan, the population density in downtown areas like Huangpu, Xuhui and Jing'an in Shanghai had decreased.

"More people from the downtown areas will move to the suburbs for better job opportunities and quieter lives due to the improved transportation system and public services in the suburbs," said Zhou.

Another trend over the last decade has seen a rise in the percentage of migrant workers with higher education.

"I noticed there are more excellent graduates from universities outside of Shanghai coming to the city for jobs, especially since 2003 as more international companies set up their offices in the city," said Chen Qian, manager of a community employment agency in Shanghai.

She added that the arrival of more professional migrant workers is a good sign to ensure the economic development of Shanghai.