[quote

ost_uid0="SSJKarma"]actually...
BEN KENOBI :"he pursued every single jedi and killed them by his own hand ! only a few sucessfully escaped him !"
that included him, yoda and probably some others that we don't know about ![/quote]
I dont' think its possible for Vader to kill off a couple hundred or thousand Jedi singlehandedly in 15 years...it just doesn't seem possible.
I also have a direct quote from a book that was compiled from Lucas interviews, the comics, movies, and the novels. It says...
"The greatest threats to Palpatine's power were the Jedi Knights, and he crushed them swiftly and mercilessly. The bloody crusade, often called the Jedi Purge, resulted in the deaths of thousands of Jedi Knights and Masters and caused the survivors to go underground. The Emperor's assistant, Darth Vader--who as Anakin Skywalker had been raised as a member of the Jedi Order--was allegedly responsible for the greatest atrocities of the Purge."