The retirement system for aged cadres was formally established in the early 1980s. Candidates for ministers, provincial party secretaries, and governors have to be younger than age 65, and those for deputy ministries, deputy provincial party secretaries, and deputy governors younger than age 60. The main problem lies in retiring top senior leaders, namely those in the Political Bureau and especially in the Standing Committee. Although Deng did not specify the retirement age for these positions, he was able to retire aged senior political leaders. During Deng's tenure, the average age of Political Bureau members reduced from 71 in 1982 to 62.1 in 1992.