Quick question about Epic Warding

[visaris7]

The wiki mentions that the protection offered by Epic Warding scales as follows:

Description: Provides damage soak of the same power as a similar level earth genasi and will soak 15 physical damage. Lasts until rest, not dispellable, no damage absorbtion cap.
* At Level 10, +5/15 DR
* At Level 20, +6/15 DR
* At Level 30, +7/15 DR
* At Level 40, +8/15 DR

The level mentioned above is overall level, and not caster level, right?
So, for example, when my PM hits level 40 with only 7 wiz levels, he will get the lvl 40 +8/15 DR, correct?

[Lokey]

Yes