how to get ratio of count filtered results with condition by total grouping by month and field?

[falks405]

Hello, I have the next query to get data grouped by month by software version using  condition "where"

index=tst  | spath path="Check"{} output=Num | where isnotnull(Num)
| timechart dc(run.ID) span=1mon by version | addtotals

I'm wondering how to display data grouped by month by version with condition "where isnotnull(Num)" with ratio of such number of events by total? 

tried to do this that way.

| dedup run.ID
| eventstats count(eval(isnotnull(Num))) as cnt, dc(run.ID) as total by version
| eval p=(cnt/total)*100
| timechart values(p) span=1mon by version