Definition: This task involves creating answers to complex questions, from a given passage. Answering these questions, typically involve understanding multiple sentences. Make sure that your answer has the same type as the "answer type" mentioned in input. The provided "answer type" can be of any of the following types: "span", "date", "number". A "span" answer is a continuous phrase taken directly from the passage or question. You can directly copy-paste the text from the passage or the question for span type answers. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words. A "number" type answer can include a digit specifying an actual value. For "date" type answers, use DD MM YYYY format e.g. 11 Jan 1992. If full date is not available in the passage you can write partial date such as 1992 or Jan 1992. If you find multiple spans, please add them all as a comma separated list. Please restrict each span to five words.
Input: Passage: However, on Tuesday, 7 February 2012, it was confirmed that Cardiff Blues would face Connacht Rugby at the Arms Park on Friday, 10 February 2012. The Pro14 League game result was a win for the Cardiff Blues 2215 and attendance of 8,000. The following Tuesday, it was announced that the match against Ulster Rugby on Friday, 17 February, would also be at the Arms Park, resulting in a Blues win, 2114 and attendance of 8,600. The agreement signed during 2009 tied Cardiff Blues to a 20-year contract to play a maximum of 18 games per season for a set fee, rather than per match at Cardiff City Stadium. But on 23 February, it was announced that the two Welsh derbies against the Scarlets and the Ospreys (rugby union) would be played at Cardiff City Stadium, rather than the Arms Park, because of Cardiff Blues anticipation that the attendance figures would far exceed the maximum capacity of 9,000. On 8 May 2012, it was announced that Cardiff Blues would be returning to the Arms Park on a permanent basis after just three years at the Cardiff City Stadium.
Question: How many years of the 20 year contract did the Cardiff Blues not play at Cardiff City Stadium?
Answer type: Number
Output:
17.