Obviously no one will ever really replace Alex Trebek, and that’s especially true for Dr. Oz.

There have been five Jeopardy! guest hosts so far, and some have definitely been better than others. If you’re wondering how they’ve been doing in the rankings, here are the numbers so far:

Ken Jennings was the first person to take the podium following Alex Trebek’s death and, so far, he’s done the best with an average Nielsen rating of 6. Jeopardy! producer Mike Richards is second with a 5.9.

Aaron Rodgers is third with a 5.6, but that’s after only one week. His second-week ratings weren’t in yet when the list was compiled. Katie Couric is next with a 5.5, and Dr. Oz brings up the rear with an average rating of 5.1.

The rating represents the number of TV households estimated to be watching a show. According to Nielsen, there are 121 million TV households in the U.S. so Aaron’s 5.6 means that 5.6% of those households were watching him.

Anderson Cooper just started his first two-week stint guest-hosting, and here’s who’s coming up after him.

— Jenn