Of the people of Laos 67% are Theravada Buddhist, 1.5% are Christian, and 31.5% are other or unspecified according to the 2005 census. The proportion of Buddhists could be as high as 98%; that religion remains one of the most important social forces in Laos. The predominant religion in Laos is Theravada Buddhism which, along with the common animism practiced among the mountain tribes, coexists peacefully with spirit worship. There also are a small number of Christians, mostly restricted to the Vientiane area, and Muslims, mostly restricted to the Myanmar border region. Christian missionary work is regulated by the government.