Update posted 04 July 2008, covering 255 boxes or 5.10% of the packaging run. On average, there have been 1.95 boxes per autograph.
Jeff, did someone get a box with more than 5 autographs? How many?
No boxes with more than 5, but perhaps a case instead?

There were 6 autos in "Case 2" from sfmuggle (bottom of first screen in the breakdown thread). It was your "Case 5", but with two autos in one of the boxes.
I include reports on less than a full case, though I realize the autos/box ratio can be off a little bit if you don't know what else was unreported from the case. Still, usually you can explain a ratio different from 1:2 boxes just by seeing occasional cases that are shorted or enhanced.