How to use timechart command across time ranges

[sudeep5689]

I have a query in splunk
index = * STATUS_CODE earliest=-2mon@mon latest=-1mon@mon | fields STATUS_CODE | rex field=_raw "STATUS_CODE:(?.{0,1}\d)"
| eval success=if(status_code in(0,1),1,0) | timechart count as total sum(success) as success
| eval success_rate=round((success/total)*100,3)
| eval success_rate=success_rate + "%" | table _time success_rate | append [search index = * STATUS_CODE earliest=-1mon@mon latest=@mon | fields STATUS_CODE | rex field=_raw "STATUS_CODE:(?.{0,1}\d)"
| eval success=if(status_code in(0,1),1,0) | timechart count as total sum(success) as success
| eval success_rate=round((success/total)*100,3)
| eval success_rate=success_rate + "%" | table _time success_rate]

I want to show the single value visualization displaying the increase/decrease in success_rate, but its not displaying correctly. I mean i need to add a timechart command again but thats not working. Can anyone help

[richgalloway]

Please explain what is meant by "its not displaying correctly". What are you getting? What are you expecting?
Have you tried removing eval success_rate=success_rate + "%" so Splunk is only displaying numbers?