At this time, bumptracker.com has far too little information to be of any use.

In order to make a good decision, you need more than just historical information. Even if you had all the airlines' data (which they aren't going to share, obviously), that won't help for future flights.

In order to select flights more likely to need volunteers, you need access to the flight's booking levels. That is also proprietary information, so your only option is to guess.

------------------
"It's as easy as 1, 2, C" -- Kelly, Married With Children