BEIJING - The gross revenue of China's social insurance funds increased 20.2 percent year on year to 2.89 trillion yuan ($467 billion) in 2012, the Ministry of Human Resources and Social Security said on Monday.

The gross expenditure of social insurance funds increased 22.9 percent from 2011 to reach 2.22 trillion yuan, the ministry said in a statistics bulletin posted on its website.

China's social insurance funds contain five parts, the basic endowment insurance for senior citizens, basic medical insurance, unemployment insurance, work-related injury insurance and maternity insurance.

By the end of last year, a total of 304.27 million working people, retirees and beneficiaries were covered in the basic endowment insurance for senior citizens, an increase of 20.36 million from a year earlier, according to the ministry.

Among them, 45.43 million were rural migrant workers, an increase of 4.03 million from 2011.