I have a report that works like the following:

John                     |    London

Joseph                  |    New York

Bill                       |    Rome

Bob                      |    London

Clark                    |    New York

I would like to count, in the table's footer, how many times each city appears in the report, like following:

London: 2

Rome: 1

New York: 2

Only the cities that appear in the report should be counted (cities with count 0 may not appear). Any ideas?

Thanks in advance.