What's Google's share with adwords campaign

I am just wondering if anybody knows what is the precentage that Google takes from sites running adwords?
In other words, if i pay google $50 per click, how much of that goes to google and how much of that goes to adsense subscriber?
Not really sure if they disclose that to adwords campaigners.

Thanks

 

They don't.

Here's some related info regarding the revenue split.

 

I haven't dug into Google's quarterly reports but it should be easy to approximate the payout from revenue and cost of sales. Google is in a nice position now if they are very profitible while giving close to 80% to publisher and can change that as needed. If they project to need to report more profit, they can tweak things to 75% or whatever they need.