average time based on clock time range

I would like to average clock times that fall within a specific time frame.

I have already calculated an elapsed time with a formula but want to find the average time between 8:00 and 20:00 and between 20:01 and 7:59.
Any ideas?

Thanks in advance

Performed time Ordered to radiology report (min)
7:20 37
8:59 61
14:24 99
17:34 105
17:47 939
19:19 77
22:46 52
22:48 66
23:06 47