"Flaps_50!" wrote:
I'd like to know how many fuel exhaustions were associated with a
successful emergency off-field landing.

The AOPA writes a yearly report on accidents (see
http://www.aopa.org/asf/publications/nall.html) that addresses questions
like that; here's the latest one:

http://www.aopa.org/asf/publications/08nall.pdf

Go to page 14 and you should find an approximate answer - at least for the
year they examined in that report.