Mod and Average when calculating time difference

Hi Excel Brain Trust,

I'm trying to find the average of time differences.

I have a range of calculated values that are time differences between two times, using the "MOD" formula:

=IFERROR(MOD(range-range,1),"N/A")

The result is formatted to hh:mm

However, I cannot seem to find the average of the results. =Average produces results that I cannot figure where they're coming from.

Any ideas? Unfortunately my client strongly prefers the hh:mm format.