Average days between dates and locations

I've seen a few topics on this but nothing specific to what i am trying to achieve.

What i am trying to do is, for each location in my data, measure the average number of days between dates for each entry by that location.

So in the sample data attached, I am trying to build a table visualisation which will list each location, and then give me the average days between each date.  However, there can be duplicate days for each location (which is correct) but if this is the case then the duplicates can be ignored as it doesnt matter how many entries are the same date.

So I am aiming for something in a table that looks like:

Telford   5.4 days

Bournemouth  8.1 days

London  9.1 days

Does this make sense?  The data is:

Thanks