Pokerstove can help you get a range like that, but what he's saying is your preflop raising should be 20%+ just on the button - less from the earlier positions.
You can't simply raise everything in that range every time because you have to consider what happens before you. If every other person folded around to you EVERY time you were on the button, then sure, raise the hands in the 20% range and you'd get that stat. But you know that's not going to happen. So the range is going to be bigger, but depending on what happens before it's your turn to act, you're throwing many of those hands away.
Just to be clear, for example:
You've got 98s.
It's not within the 20% range you'll find on stove.
But if everyone folds to me, I'm stealing with it because it's a playable hand.
If I've got limpers, I'm calling along with it to try and hit a big hand. I'm not going to raise with it because I'm not trying to pick a fight with it and go heads-up for a big pot.
If I've got even 1 raiser, I'm folding it every time.
So do some reading in the stickies and other threads on here. Search "starting hands" and read the first dozen threads that pop up. After you've focussed on it for a while, you'll grasp the range that you're playing from different positions at the table and you'll see your stats move the direction they're supposed to.