Starkonjas Head - Evasion Rating Affix is Global?

My Starkonjas Head has 610 Evasion and when I replace the helmet with Alphas Howl which has an evasion rating of 573. My Evasion on my character goes from 51% all the way down to 20%.

And no im not on low life.

Is the "Increased Evasion Rating" Affix global instead of local?

Or is the difference between 573 and 610 in terms of evasion just a lot?