Make life easy for yourself and say its a "hybrid system" of wage determination, and it actually is, particularly under FWA.
And no, don't say it "peaked in 2008" , rather, just keep it low key and say, FWA has resulted in more regulations etc with BOOT test and all that, that should do it,
But also, don't blame australia's low productivity growth on FWA, markers will hate that, as it was only implemented in 2010 so our current productivity rates are not really a true reflection of its effectiveness.