There are likely too many stores and too many factors for anyone to give you even an approximate figure. It depends mostly on the specific store's sales/performace goal as set forth by corporate for any given year. Greatly exceed your goal, you get a great bonus. Work in a very established store without much patient addition/turnover/sales change? Not so much.
And there doesn't seem to be a consensus on exactly how Walmart comes up with each store's goal. One of the best scenarios seems to be to take over a brand new store that isn't expected to do much and rock the house your first year. Just realize your goal would then reset and your second year bonus wouldn't be much. Moreover, it's all a matter of luck in placement and timing.