I forgot to keep a death count but I think it was quite a few. Besides the problem of distinguishing between probably dead and definitely dead there is the issue of how to deal with resurrections. If someone gets resurrected does one deduct from the death count?
Wolverine's heart stopped and he died… but he came back. Yashida died… but he came back. Professor X had been dead since X-Men: The Last Stand in 2006… but he came back too.