Bulgaria is officially a secular nation and the Constitution guarantees the free exercise of religion but designates Orthodoxy as a "traditional" religion. In the 2001 census, 82.6% Bulgarians declared themselves Orthodox Christians, 12.2% Muslim, 1.2% other Christian denominations, 4% other religions and zero percent atheists. Most citizens of Bulgaria have associations at least nominally with the Bulgarian Orthodox Church. Founded in 870AD under the Patriarchate of Constantinople , the Bulgarian Orthodox Church had autocephalous status since 927 AD. The Church became subordinate within the Patriarchate of Constantinople, twice during the periods of Byzantine and Ottoman domination. It was re-established first in 1870 in the form of the Bulgarian Exarchate, and then in the 1950s as the Bulgarian Patriarchate.

What percentage of Bulgarians are non-Orthodox Christians?
1.2%