As it stands, it's still currently a derivative text. Some of it may have been rewritten, but other parts of it, including the trivia section, include the same basic formatting and convey the same information in a very similar way. Under the CC-BY-SA license, that makes it a derivative that must still be attributed.
There seems to be some sort of stigma here regarding the attribution notice. Although you should strive for original content, there's nothing wrong with re-using text and then attributing it. That's what the Creative Commons license was created to do, to allow for the reuse and remixing of information like this. I wouldn't worry about spending too much time trying to rewrite it; as long as you keep the attribution notice, you're golden.