english: Well, the thing is that, the congestion charges, they were introduced first as a trial, so they were introduced in January and then abolished again at the end of July, followed by a referendum, and then they were reintroduced again in 2007, which of course was a wonderful scientific opportunity.
non_english: De opstoppingstaks werd eerst op proef ingevoerd, in januari, en eind juli weer afgeschaft, gevolgd door een referendum dat hem weer invoerde in 2007. Een buitenkans voor de wetenschap.