I want more character slots

I want more character slots on my solo server :< I know some people in my guild who have 11 90s and don't want to level on another server so they have drifted off wow and onto eso. PLEASE for their euwowgold sakes and my sake and everyone else's sake who wants/needs more slots, PLEASE add more room per solo servers. I have 11 toons atm, all of which are 90 as well. I am dying to make more toons.