On our fuchs there is a speed sensor on the drum and another that pick up off a sticker placed on the rear tyre in an attempt to negate wheelspin losses.
Also, not all Fuchs have sensors that pick up real RPM, and therefore they try to use maths (via the dyno operator typing in the bikes gearing) to work out the horsepower. However a worn tyre, or modified gearing would effect the readings dramatically.
.... and then (sorry about this), I dont see any SEA statement on the chart so it doesnt look like he has the weather station box fitted, so it may have been a hot day and was not corrected for weather conditions. Go back to the same dyno and it may read differently. Try a cold day, your bike will be more powerful (cheeper than engine work).
So assuming that this dyno center HAS got the weather station, and he HAS hooked up the RPM unit, so the wheel figure IS acurate ...
... the fuchs software (like a lot of dyno's) tries to work out the crank figure by using the spindown to work out pumping losses (rev the bike through, hit the clutch, and let the roller drag the engine back down the revs). Which is sort of OK for a guide, but inacurate.
The factory would have used an engine dyno, which would have given much more acurate readings.
Somewhere in there is your missing 10%. Oh and add in some ram air for good measure (why not, all the Jap companies do).
PS Who was it who said "lies, damn lies, and statistics".