A survey by the National Institute of Statistics in 2017 showed that 95.3% of the population in Phnom Penh are Khmer, 4% Chams, and 0.7% others, predominantly Chinese, Vietnamese, and other small ethnic groups who are Thai, Budong, Mnong Preh, Kuy and Chong. The state religion is Theravada Buddhism. More than 90% of the people in Phnom Penh are Buddhists. Chams have been practicing Islam for hundreds of years. Since 1993, there has also been an increase in the practice of Christianity which was practically wiped out after 1975 when the Khmer Rouge took over. The official language is Khmer, but English and French are widely used in the city.