I think it depends on what the reference impedance is for your 12 mV and it depends on what the reference power or voltage level is for your SoundProfessionals. Neither of those specs tell the whole story, although there may be some reference values that are commonly assumed for mic specs. I think Brian Skalinder has dissected mic specs before and he might know how to compare your numbers according to standard references. Also, poorlyconditioned has been through the mic sensitivity math before and may know how to compare your numbers.
Do you know if your -35 dB is a voltage spec or a power spec? If it's a voltage spec (and I suspect that it is) and both mics are assumed to be driving the same reference impedance, then you'd just take 20 log (.012) = -38.4 dB, so your -35 dB mics would be louder.