Using the scorecard results to get the rate

I have 2 scorecards, 1 is for Total Leads (date range filter is on “Created On”), 2nd is Won (Date range filter is Installed On). How can i use those scorecard results to show the Win Rate?

What I tried:
-Variables (Only text and cannot use as formula)
-Blend (not giving accurate field value)
-do it in spreadsheet and use in looker (not date range filter friendly)

Ran out of options.

Need Help! Thanks