In 1980, General Secretary and reformist Hu Yaobang visited Tibet and ushered in a period of social, political, and economic liberalization. At the end of the decade, however, analogously to the Tiananmen Square protests of 1989, monks in the Drepung and Sera monasteries started protesting for independence, and so the government halted reforms and started an anti-separatist campaign. Human rights organisations have been critical of the Beijing and Lhasa governments' approach to human rights in the region when cracking down on separatist convulsions that have occurred around monasteries and cities, most recently in the 2008 Tibetan unrest.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did monks in the Drepung and Sera monasteries start protesting for independence?
1989