Don't think there's a way for the pivot table itself to do that, but it's
just as easy to:
create the pivot
in the cell to the right of the pivot type:
=B3/C3
and copy down.
Change to percentage formatting...

(Of course, this assumes B3 and C3 are the cells the values are in. Change
as appropriate.)

"joel" wrote:

I'm talking about something like

Street Homes_with_DSL Number_Homes_on_Street
Elm 3 20
Oak 10 35

and so on. How can I make a pivot table that automatically gives %
Homes_with_DSL per Street?