racedo, well the most important airport for Surrey according to the UK CAA survey for 2011 was LGW with 2.2 million passengers with LHR in second place with 2.0 million. Third is LTN with 0.8 millon and fourth is STN with 134,000. Since BOH had only 690,000 passengers in 2012, I don't think for Surrey it will reach the STN levels. I think it's better to know than just will guessing.
Problem with surveys is that you only get the answers of the people who answer not those who don't or who cannot be bothered to stop.