Credit score increases?

I know there is no set answer, but I'm curious to know how long rebuilding my credit will take. My question is, what is the range of points you will go up each month if you're making timely payments and your balances to credit ration is less than 50%? I mean, is it 1 point or is it 50? Any idea would be helpful. I'm going to get my balances to stay under 25% soon, as well.