Donnis......you will have a great deal of trouble removing the stain - if it has adhered well.
A few years is about all you are going to get with a floor type coating exposed to the elements - paint or stain. Dull and pitted is what happens as the product ages.
As long as your surface is clean and is stuck - go ahead and go over it with a good floor paint - or if you are in a southern clime - another coat of the same concrete stain that was used previously.
Any solid coating (concrete stain or paint) CAN peel - there is no guarantee on that. Proper surface prep and following the application directions will lessen the chance of having a coating peel.