A two-year study by Pew Research of 199 countries and self-administering territories found Islam to be the world's most common state religion, and listed ten non-religious nations that are hostile toward Christianity and other religions. Most countries do not have an official or preferred religion: of the 43 nations which do, 27 follow Islam. Thirteen states have Christianity as their official religion, two have Buddhism, and one has Judaism. The study said that there are nine officially Christian countries in Europe, including the UK, Denmark, Monaco, and Iceland. The others are Costa Rica, the Dominican Republic, and Tuvalu (in the Asia-Pacific region). Only Zambia in sub-Saharan Africa is officially Christian.