Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

Oklahoma's centennial celebration was named the top event in the United States for 2007 by the American Bus Association, and consisted of multiple celebrations saving with the 100th anniversary of statehood on November 16, 2007. Annual ethnic festivals and events take place throughout the state such as Native American powwows and ceremonial events, and include festivals (as examples) in Scottish, Irish, German, Italian, Vietnamese, Chinese, Czech, Jewish, Arab, Mexican and African-American communities depicting cultural heritage or traditions.
When was Oklahoma's centennial year?