1:1 is break even (giving back 1 full copy of what you've downloaded). 2:1 is much better. Looks like your ratio is just over 2.5. I'd say that's pretty good, assuming you don't have a lot of leachers left.

I usually let mine go to about 2:1 unless there aren't any seeders. If I'm the only one, I have had cases where it gets to 5:1, but that's extreme. I also leave my computer on all the time. I also haven't seeded anything in a LONG time.

You might want to just stop seeding and see if anyone complains. I've done that before. If no one complains, then either no one cares or it's being seeded by someone else.