Need to ignore rows with text before using another function

I track the dates I start a task and the date it is returned to the client. I wanted an average of the times so used the below formula. Sometimes a task gets put on hold so I want to exclude those tasks which would be signified by text in row 'U' (the text varies due to different reasons for holds).

I am using =(SUM('Tracker'!Q:Q)-SUMIFS('Tracker'!D:D,'Doc Executions'!Q:Q,">0"))/COUNTIF('Tracker'!Q:Q,">0") to get the average of the dates but this includes rows that were on hold which bumps up my average.

Tracker is the name of the sheet

Column Q is the return date

Column D is my start date

Thanks in advance!