Say Barry, could you use this site's "answer your own question" feature to give us some tips on how to find data that may not be readily available?
This is a community wiki answer: please add to it.
Tips for finding hard-to-locate data:
Figure out who's interested in the data and visit their website. Governments generally have the most data, but non-profit organizations (including international organizations) often compile large amounts of data as well.
Consider free registrations on sites that offer data. Search engines generally can't index data that requires registration to view (though some registration sites allow search engines special access). Registring might give you access to data that's online, but not available to search engines.
Email or call people who might have the data. There's a lot of data on the Internet, but it's not everything. Sometimes, contacting an organization directly will help you obtain data that's free, but not posted on a website.
Contact a librarian. Librarians do a lot more than shelve books: they can help you find information, both online and offline. The information you need may be in a printed book you can borrow for free.