Here's a general answer...
Devil,
If you look at your typical power curve... probably you need (apprx) 2 to 3 times the power to hover than to cruise at the bottom of the U in the power curve (55 knots ish). For a rough percentage IGE and OGE are pretty close compared to the base of the power curve so "2-3 times" is good enough for casual conversation. Nearer the onset of ETL at 15 knots or so there will not be quite such a difference...