COunting conjugacy classes in out (F_n)

We show that if a finitely generated group G has a nonelementary WPD action on a hyperbolic metric space X, then the number of G-conjugacy classes of X-loxodromic elements of G coming from a ball of radius R in the Cayley graph of G grows exponentially in R. As an application we prove that for N ≥ 3 the number of distinct Out(FN)-conjugacy classes of fully irreducible elements Φ from an R-ball in the Cayley graph of Out(FN) with log λ (Φ) of the order of R grows exponentially in R..