[canvia]

Are most of their employees younger?

"Disclosing that information could only result in neutral or negative outcomes for me. It is not logical for me to behave in such a manner. Do you generally hire people that make illogical decisions?"

If they're asking you for detailed salary information like that the answer to the above question is going to be yes regardless of what they say. Don't accept that kind of abuse of information asymmetry. If they behave that way during the hiring process, imagine how they will behave once you have committed to the job. Find a better place to work IMO.

The government publishes transparent salary information for over 800 types of jobs, segmented by state. http://www.bls.gov/bls/blswage.htm