You will be given a definition of a task first, then some input of the task.
This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: Washington University has been selected by the Commission on Presidential Debates to host more presidential and vice-presidential debates than any other institution in history. United States presidential election debates were held at the Washington University Athletic Complex in 1992, 2000, 2004, and 2016. A presidential debate was planned to occur in 1996, but owing to scheduling difficulties between the candidates, the debate was canceled. The university hosted the only 2008 vice presidential debate, between Republican Sarah Palin and Democrat Joe Biden, on October 2, 2008, also at the Washington University Athletic Complex.
Output:
In what year was the Washington University Athletic Complex built?