Graham defensive rule #5?

I'm confused on rule #5. Could someone help clarify it for me?

5. A minimum increase of at least one-third in per-share earnings in the past 10 years.

Should this calculation be the average EPS for the last ten years compared to year #1? Or this year's EPS compared to 10 years ago? I can read this rule a couple different ways.

Thank you for your forum post, Rooster67fl!

This Graham rule and the way it's applied on Serenity is addressed in detail at Graham Rating - Earnings Growth.