How many aircraft does an ATC controller usually handle at the same time? My question relates to the question What is the maximum number of planes a controller can control?, which asks about the maximum limit. One comment indicated 35 aircraft per hour for en-route segment. I, however, are not interested in the maximum number of aircraft per sector, but in the typical number of aircraft. 

I am now interested in the typical amount of aircraft per enroute Air Traffic Controller at any given time during the day (how many aircraft are handled at the same time by an en-route controller).

While I am sure that there is no universal ground truth, can anyone report experience? To limit the scope, let's assume continental U.S. or Europe during the day, upper airspace.
Depends entirely on complexity, rather than sheer numbers. In ATL I can comfortably handle somewhere around 60-70 departures per hour from a ground control position. More than double that when you factor in arrivals. That’s a VERY low complexity situation, with everyone moving one direction. 

On the flip side, I’ve worked TRACON radar positions with five aircraft dodging severe weather and worked my ass off. High complexity. 

ARTCC sectors are different in that they have known numbers, and will go from green to yellow to red depending on saturation. These are based on routings, in trail restrictions and so on. Again, all complexity.