But he adds that it will be two years before tourism in the valley returns to normal.

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If a normal number is 50 or more, then Silicon Valley won't have to change much.

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OK, in Silicon Valley, such grand thinking is pretty normal.

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The report found no definite reason why the helicopter had flown up the valley at low altitude after "abruptly breaking off what appeared to be a normal approach to land at Rochester airport".

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But if the normal number is closer to 20, with 50 seen only in bumper years, then Silicon Valley will have to find other exits for its startups.

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Thames Valley Police said the dark coloured private hire car, which may have had the appearance of a normal car, could have then made a drop off in the early hours of Thursday.

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