Gene, that plant is probably border line. Did you get the plant that way or did you remove it from a parent plant?
Plants with a lot more than say 50% variegation are really hard to keep alive after they are removed from their parent - which would be providing it with a lot of the nutrients and products of photosynthesis that it itself has a hard time producing enough of.
Keep it on the dry side and provide as much light as you can without getting the plant too hot, then keep your fingers crossed. I have not had much luck with keeping such heavily variegated plants alive for long without them still being attached to the parent, but I hope you manage to. If it does survive it will be very slow growing.
