  The aim of this work is to examine the exponential rates at which
entanglement distillation occur in three-qubits systems. The approach we will
follow to elucidate the entanglement concentration is based on the Schur-Weyl
decomposition and the Keyl-Werner theorem. In order to clearly state the main
results of this work we will have to introduce the notion of SLOCC equivalence
and the covariant algebra which will allow us to classify states in different
\emph{entanglement classes}. Our main results comprehend the asymptotic rates
for the probability of being in an invariant subspace in the Wedderburn
decomposition of the state with effective Kronecker coefficient
$g_{\alpha\beta\gamma}=1$. We will also present a combinatorial formula for the
effective Kronecker coefficient for two-row Young diagrams. With this work we
hope to shed some light in the way a multipartite system is entangled and at
which rate can we convey entanglement for further applications.
