How to calculate Percentage of particular events out of total events.

I want to find the percent of events with the key word error out of all the events recorded during a time window I have the following query in place but the result generated is 0.0000% index=XXX "*" | stats count AS "Total", count(eval(eventMessage=="error")) AS Failure|eval Failurerate=(Failure/Total)*100|table Failurerate