XINING, March 14 (Xinhua) -- The population of the plateau province of Qinghai in northwest China has exceeded 6 million, four times the number 70 years ago when the People Republic of China (PRC) was founded.

By the end of 2018, Qinghai's population reached 6.03 million, up 0.81 percent than the previous year, the provincial statistics bureau said Thursday after a sampling survey.

The province is home to 54 of China's 55 ethnic minority groups, with Tibetan being the largest, accounting for one-quarter of the entire population.

Located on the Qinghai-Tibet plateau with an average altitude of 3,000 meters, Qinghai is one of the least developed provinces in China. When the PRC was founded in 1949, there were only 1.48 million people in the province.

Due to the improved living and medical conditions, Qinghai has improved in both population number and life expectancy over the past decades.

The average life expectancy of the province rose from 60.79 years in 1981 to 71.70 years in 2018. A total of 155 people are centenarians, according to the survey findings.