Mark RV,
I looked at the survey and I think that the way that bikes are used by most in the US is much different than in The Netherlands. Here for most people they are for pleasure and or as a secondary means of transportation. One exception might be College students. In The Netherlands and other urban environments it is common for a bike to be a primary means of transportation. As a result you might find that the responses to your survey from the US are very different than from respondents in the EU or Asia.
Good luck.
By the way we our son is considering a semester to full year of study in Delft. It's a really nice place.