The pivot field list, that allows to drag and drop and edit the summarize method ( probably same as #13), would work as a frontend to the fields array.
Calculated fields, or: write a formula between columns (use case: one column for delayed events, one column for total events, calculated column with average)
This article contains 2 nice Excel pivot functionalities http://chandoo.org/wp/2010/01/27/pivot-table-tricks/