How to make timechart with ratio failed/total ?

[AnaSpiStats]

This is my search:

message_data_type=gd*| timechart count by message_data_type limit=10

These are my results:

But I need to create a timechart of the  failed/total events ratio.

How can I do that ?

[AnaSpiStats]

failed/Total events 

[ITWhisperer · Accepted solution]

| timechart count by message_data_type
| addtotals col=f row=t
| eval failedratio=failed/Total
| fields _time failedratio Total

[ITWhisperer]

Is that what you really want to do? What if there are zero failed events - Success/zero is infinity, or Failed/zero is infinity if there are zero Success events?