Hi @jim.lucas -- flight ratio is the % of time that you're in the air (neither foot is on the ground).
We calculate it as follows :
Flight Time = (CycleTime - 2*ContactTime) / 2 [Note: CycleTime is the inverse of Step Rate]
Flight Ratio = FlightTime / (FlightTime + ContactTime)
Flight Ratio naturally tends to get higher as your pace increases, so if you're, say 23% at a 5:30 pace, that might be Average, but 20% at a 7:00 pace would be High. Hope that helps.