From :
We know that there are more than P% conductors and less than Q% conductors.

To clarify, you should write :
By percentage, we know that there are more than P% conductors and less than Q% conductors of all Russian citizens in this city.

Until I've read several comments in discussion, I found out what the problem wants.
Sincerely.

I added a little clarification to the sentence about percentage and a hint about sample test. Now the problem statement should be easier to understand.