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: In the run-up to the London 2012 Summer Olympic Games and London 2012 Summer Paralympic Games, Eton's purpose-built Dorney Lake, a permanent, eight-lane, 2,200 metre course (about 1.4 miles) in a 400-acre park, officially known throughout the Games as Eton Dorney, provided training facilities for Olympic and Paralympic competitors, and during the Games, hosted the Olympic and Paralympic Rowing competitions as well as the Olympic Canoe Sprint event, attracting over 400,000 visitors during the Games period (around 30,000 per day), and voted the best 2012 Olympic venue by spectators. Access to the 400-acre parkland around the Lake is provided to members of the public, free of charge, almost all the year round.
In what year was Dorney Lake built?