Albania is a secular state without an official religion, with the freedom of religion being a Constitution of Albania right. The 2011 census, for the first time since 1930, included an optional open-ended question on religion; the census recorded a majority of Muslims (58.79%), which include Sunni (56.70%) and Bektashi Muslims (2.09%). Christians,  making up 16.92% of the population, include Roman Catholics (10.03%), Eastern Orthodox Church (6.75%) and Evangelicalism Protestants (0.14%). Atheists accounted for 2.5% of the population and 5.49% were non-affiliated believers, while 13.79% preferred not to answer.
Question: How many years had it been since the last time Albania included religion on the census prior to the 2011 census?
Answer: 81