1987 420 SEL with about 95,000 on the clock now

generally I get:
14-18 MPG city, depending on how much I push the go button
19-21 MPG highway, again, depends on how often I push it hard to pass someone.

I have a spreadsheet with approximate MPG for the last 30 fill-ups or so if anyone wants to take a look. I try to keep statistical data to see if any of the repairs I make change the milage at all. I can't be too sure of how accurate each different gas pump is at measuring the dispensed quantity, and also if I fill it up the even close to the same amount each time or not.