Charts in Reports module

Hello.

I understand that my questions can be stupid, but hell…I can’t understand how to create charts properly by myself and hours of search in google didn’t gave the answer.

Just simply, how do you create them?!? For example I have 500 cases with status or open or close. I need to create pie that show me number of open cases and number of close cases. That’s all.

I’m working with:
Version 7.7.6
Theme: Suite R