SOH is a measure of internal resistance that happens to correlate exactly with remaining capacity. So a SOH of 90% means 90% remaining capacity. (Hx measures the same thing, but it's more like a snapshot of the moment, and SOH is more like an average over a longer period.) My 2013 SV has 16.6k miles on it, BTW, and still has 12 bars, although that may change this Summer.
2013 "Brilliant Silver" SV with Premium and no QC, a 2009 Vectrix VX-1 W/18 Leaf modules, and 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.