What XPMorten says about the relationship between engine speed and thrust is absolutely true, in fact, that relationship has hardly changed over the decades. Engine thrust is APPROXIMATELY proportional to the engine speed raised to the power of 3.5, versus speed squared for a propeller aircraft.
What HAS changed in more modern engines is the relationship between TLA (Thrust Lever Angle) and Net Thrust. The Engine Speed Vs Thrust is pretty much unchanged.
Regards,
Old Smokey