When did Shanghai social security begin to pay?

According to official website of Shanghai Human Resources and Social Security Bureau, 1993, Shanghai began to implement the reform of the old-age insurance system, expanding the original "unit guarantee" to "social security", and the guarantee funds were also changed from the original small units to social pooling. While helping enterprises with heavy pension burden to participate in market competition fairly, they also accelerated the accumulation of security funds through government investment to ensure that retirees' pensions were paid in full and on time.