Dashboard tracking converted Leads/Opportunity/Prospects per Month

Dashboard tracking converted Leads/Opportunity/Prospects per Month

Hi guys,

I'm trying to create a dashboard that shows how many Deal Flows are converted (Lead --> Opportunity; Opportunity-->Prospect; Prospect--> Won;....) per month. 
Unfortunately, I only can "find conversion time" the dropdown menue. 

Thanks in advance for your help!

Flo