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.

Example input: Passage: In 1763, Spain traded Florida to the Kingdom of Great Britain for control of Havana, Cuba, which had been captured by the British during the Seven Years' War. It was part of a large expansion of British territory following the country's victory in the Seven Years' War. Almost the entire Spanish population left, taking along most of the remaining indigenous population to Cuba. The British soon constructed the King's Road connecting St. Augustine to Georgia. The road crossed the St. Johns River at a narrow point, which the Seminole called Wacca Pilatka and the British named "Cow Ford", both names ostensibly reflecting the fact that cattle were brought across the river there.
Example output: Who owned Cuba after the Eight Years War?
Example explanation: This question appears to be relevant to the passage as both involves words such as 'Cuba' and 'War' which also exist in the passage. The passage mentions that "after the war, almost the entire Spanish population left, taking along most of the remaining indigenous population to Cuba". This information is not sufficient to conclude that which country owned cuba.
Q: Passage: In 2005, the Office of Fair Trading found fifty independent schools, including Eton, to have breached the Competition Act by "regularly and systematically" exchanging information about planned increases in school fees, which was collated and distributed among the schools by the bursar at Sevenoaks School. Following the investigation by the OFT, each school was required to pay around 70,000, totalling around 3.5 million, significantly less than the maximum possible fine. In addition, the schools together agreed to contribute another 3m to a new charitable educational fund. The incident raised concerns over whether the charitable status of independent schools such as Eton should be reconsidered, and perhaps revoked. However, Jean Scott, the head of the Independent Schools Council, said that independent schools had always been exempt from anti-cartel rules applied to business, were following a long-established procedure in sharing the information with each other, and that they were unaware of the change to the law (on which they had not been consulted). She wrote to John Vickers, the OFT director-general, saying, "They are not a group of businessmen meeting behind closed doors to fix the price of their products to the disadvantage of the consumer. They are schools that have quite openly continued to follow a long-established practice because they were unaware that the law had changed."
A:
In what year did Sevenoaks School open its doors to students?