Sorry, won't be able to get back to you until Monday or Tuesday (weather permitting).
But, I expect that what I'll say is that the "input level meter" is there to show if people are seriously underdriving the unit (which often happens), and is not a comprehensive dynamic range indicator. The H9 is a guitar pedal and not a studio line level instrument – ears are usually best.
Our problem is that we need a good input level to overcome noise produced by the high input impedance (and the A/D conversion). Further, we have a non-linear soft-clipper on the input, and the effects are also very sensitive to the source and the settings . For all these reasons, the figures you seek are not available and, if they were, would vary from effect to effect.