I have not seen ED 2 broken down separately for most schools – in fact, those stats for ED in the chart you have are for as 2 rounds of ED combined.
What you should know, though, is that it isn’t uncommon for students who got rejected at Stanford, for example, (or any of the SCEA schools that actually reject applicants in the early round) to decide to do ED2 applications to selective LACs… IOW, that ED2 pool may not have many athletes in it but it’ll have lots of unhooked talent in it. It’s a great way for the schools to lock in students they want. So it is often a strong pool that admits fewer students.
With that said, I do think that using ED2 for another bite at the apple can be a good strategy. But as we noted above, if you are deferred in the ED1 round (which is what happens more often than being rejected), you need to be comfortable with the possibility that you will get into your ED2 school and have to pass on seeing what happens at your ED1 school.
Because you are a junior, you have some time. Definitely plan to visit any school that you might want to put on your ED list while it is in session. Check to see when you can interview on campus – many will only talk to juniors in late spring. On campus interviews are a great way to get current information about what interests you - alumni interviews are more about showing interest.
I would recommend you follow some of the threads here on ED at the schools you like because you will see how it unfolds in real time.
And FWIW, the kids from our school who have chosen Grinnell are more artsy. (More theater, less sports!)