To be more precise check this:
http://www.juventuz.com/forum/showpost.php?p=2612215&postcount=1
So far he does have the best goal/minutes ratio of all our attackers, but it's very early in the season and 1 goal can make drastic changes in the numbers.
1. Iaquinta 1 goal / 114 minutes
2. Amauri 1 goal / 146 minutes
3. Quagliarella 1 goal / 157 minutes
4. Del Piero 1 goal / 214 minutes
One goal can put each one of them on top of this list. These stats can be meaningful only after half season or something.