I can't be a%$ed reading through this thread to see how closely the actual wording has been
discussed - the trolls are strong here, I can see - but ISTM that you should tell it like this:

"Why is it that more people die on their birth('hidden' small pause)day than on any other?"

Don't repeat it, adopt smug expression, leave the pub with a trail of annoyance behind you...

J^n