Calculation average of last 10 items in a list

Whats the function to take the average of the last 10 items in a list. The list is dynamic, more number will get added to the list and when they do I want to take the most recent or last 10 average. I think I need to use … items from # function which returns a number from the #th to the end … however I don’t know what to put in for the #th… this number will always change depending on how big the list is… any help ? Thanks :smiley:

:last item index nr -10 (minus ten)