@bbrass You might want to read up on adrenal insufficiency and understand that this can be a problem when tapering if your adrenal glands don't want to wake up. There are plenty of Mayo Connect chats on tapering and adrenal insufficiency. You could start right here by using the Search feature.
I'm not sure what the range is exactly but what I do know is that your adrenal glands worked well for decades then steroids came along and put them to sleep. They published somewhere between 3-10mg a day which was exactly what my body needed. I personally hit the pain wall around 4mg and have to go down by 0.5mg after that and very slowly. I even alternately when I wanted to taper. That approach works for me.
Above 10mg you can do just about anything and not have a problem which is why they suggest 5mg tapers to get to 10mg a day. Tapering is part art and part science.