You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Portugal

Context:
According to the 2011 Census, 81.0% of the Portuguese population are Roman Catholic. The country has small Protestant, Latter-day Saint, Muslim, Hindu, Sikh, Eastern Orthodox Church, Jehovah's Witnesses, Baha'i, Buddhist, Jewish and Spiritist communities. Influences from African Traditional Religion and Chinese Traditional Religion are also felt among many people, particularly in fields related with Traditional Chinese Medicine and African Witch Doctors. Some 6.8% of the population declared themselves to be non-religious, and 8.3% did not give any answer about their religion.

Question:
What percentage of the Portuguese population did not give an answer for their religion in the 2011 census?

8.3%