Not really fair to judge stas on Muzza against last year IMHO.
Last year he led the line, and was firing shots at keepers of one League lower. Now he's really acting as a decoy to Zaha and others up front at Palace, no surprise then that'he's not getting in the penalty-box as much as he did last season.
It was more for a point of reference for Ashley's stats from last year than to compare them to this year's.