The results are in the freely available PDF, since Sparkfun are nice. I started to wonder where the numbers went, before I came to the very end and the link to the whitepaper. :)

To summarize, here are the findings how to design mouse bites according to their research:

- Hole Diameter: 0.015"

- Hole Center-to-Center Spacing: 0.025"

- Maximum Tab Width: 0.118"

- Holes should extend into the corners of the tab.