Do you know about High paying keyword of Google Adsense?

Hi, I know that google adsense is the best way of online earning.  But I know that some people earn a lot of money from google adsense form low traffic. And many people works hard, get a lot of traffic but their earning is low. I'm one of them. So I want to know - Which are the high paying keyword of Google adsense? Which are the Most Expensive Keywords in Google AdWords Advertising? Thanks