Q: 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: The cup triumph was also Everton's passport to the Cup Winners' Cuptheir first European campaign in the post-Heysel era. Progress under Joe Royle continued in 199596 as they climbed to sixth place in the Premiership. A fifteenth-place finish the following season saw Royle resign towards the end of the campaign, to be temporarily replaced by club captain, Dave Watson. Howard Kendall was appointed Everton manager for the third time in 1997, but the appointment proved unsuccessful as Everton finished seventeenth in the Premiership; only avoiding relegation due to their superior goal difference over Bolton Wanderers. Former Rangers manager Walter Smith then took over from Kendall in the summer of 1998 but only managed three successive finishes in the bottom half of the table.
A:
In what season did Heysel stop managing Everton?