Cartridge Output At Different Speeds

[Number95]

Sorry if it is dumb question, mostly the cartridge specs in terms of output given as mV at 5cm/s, but there are also some others with output measured at 3.54cm/s. Is it right to assume a linear relationship between cartridge output and speed? I mean does a cartridge output of 0.4mV at 3.54cm/s correspond to 0.565mV (which is 5/3.54 x 0.4)?

Thanks for the advice.