Finding maximum value of a custom field and showing in dashboard

[sahere]

Hi all

I have a text custom field named as "rq num" which is in the create screen of "task" issue type. I want to create a dashboard so that show the maximum value of this field among all "task" issues of the project. Could you please advise me about this?

It is noted that type of this field is text but filled by numbers.

Many thanks

[Michael March]

It is highly suggested, if possible, that you convert that custom field to a "number" type. 

If you can not, may you can setup up some automation that will update a companion field with automation what copies the value from the current field to a numeric. Have your dashboard filter use the copy (and it will have the proper sort order).