I don't know how to answer that question specifically. I went a did a little search and found two FAA publications online. Look up "tail down force" and you will get some examples.
The material says there are two components of tail down force.
1. Static - the aircraft is generally nose heavy because the center of gravity is ahead of the center of lift.
2. Dynamic - there is some value where the aircraft is at it's maximum forward center of gravity where the tail must exert the greatest possible force.
The actual value of the force is somewhere between those two positions.
I don't have an answer as to the actual value in pounds of what ever other unit is used. It would obviously depend on the design and the size of the aircraft.