What percent of criminally accused plead guilty at arraignment?

I met a lawyer at a party that said it was 95%. I thought she was joking, but aftwards I mentioned that to someone and they said she probably meant “eventually, after a plea bargain”. That a great many plead innocent at the arraignment just as a bargaining chip.

So how many plead guilty the first time they get the chance?

And is it different in places that don’t allow plea bargains (Alaska, I think)?