To view your leads report navigate to menu item Reports from the aside menu and click Leads.
Once the General Report page is opened, click on Switch to staff report.
You can view the following reports:
Weekly
Sources
Monthly
Staff
Only leads that belongs in the default status Customer will be taken as converted leads, if the lead belongs to the default status customer and its not converted to customer will be still counted as converted lead
If you want the reports to be accurate you need to assign the lead to the default system status Customer if you have conversion.