LS with du divided by ls wc-l sub directory average

Hi.

I am trying to write a script that will create a list of directories with their total disk usage (including subdirectories) divided by the number of sub directories.

so i run an ls like this ls -d */images/*/, and that would give me my list. Then i want to get the du of every directory returned in that list, but divided by the number of subdirectories in it. Thereby giving me a subdirectory average of every directory in the output.

Thank you for any help.