You're not reading that link properly, but it's understandable since the link isn't the clearest. A specific version of Firefox has the 4% you mentioned, Firefo

You're not reading that link properly, but it's understandable since the link isn't the clearest. A specific version of Firefox has the 4% you mentioned, Firefox 49. Look a little lower down and you'll see Firefox 50 has another 3% on top of that, and so forth.