Cycle ops Mag resistance setting

I have an old cycle ops mag trainer with no numbers on the manual resistance knob. Is “Level 5” the highest or lowest resistance?

I assumed 5= highest but I seem not to be able to generate anywhere near enough power on the highest resistance (I’m dying trying to push out 1.2-4 watts per kg). I may just be in lousy shape, but I am hoping I’m just using the wrong end of the scale. I can at least hit, but not hold 2+ watts/kg if I use the other end of the range. Thanks!