Quest on the Shaman line of SlowsFollow

I have no idea what the % is however I would say this is the most powerful line of spells that my 32 Defiler has. For instance, I was grouped in Runnyeye yesterday and we took on a red^^ mob. The first time we fought him I was resisted 4 times on Degeneration adept1 and the entire group was wiped out after I ran out of power. The second time we fought him I landed Degeneration on him 3 times and we were able to take him down. I was left with about 40% power as well.

In soloing, the slow spell is the first one I cast on the mob. It makes the difference between an orange con being an easy fight in which I have about 60% power and 80% hps left or it being a tough fight and I wind up with about 20% power and 50% hps.

In short, casting the slow spell line is an absolute must for any mob that is going to live longer then about 15 seconds.