Why do the two countries exchange the list of nuclear centers? [originaltext]

India and Pakistan have exchanged lists of their nuclear centers. The exchange took place as part of an agreement that bans the two opposing nations from attacking such centers. India and Pakistan have traded these lists on the first day of the year since 1992. They signed an agreement calling for the action in 1988. India and Pakistan have fought three wars since 1947. In 1998, both countries tested nuclear weapons. Relations have been tense since the terrorist attacks in Mumbai in November, 2008. India accuses the Pakistani militant group, Lashkar-e-Taiba (虔诚军) , of carrying out the attacks.