These are the results after 13 hours of having an admin user. Most of the attempts are coming from 18.104.22.168.
It is interesting that the most commonly attacked user is the admin user, but as I suspected, they will also attack other accounts too (daily-bot and seanja were also targets). At the rate they are going it will take ages to actually get in. Unfortunately for them the admin account is nothing more than a subscriber level account with a fake email address attached to it.
That might be a good way of blocking ips actually. If they try to login to the admin account more than once, give them the boot. You can click on the ip addresses to see where they are coming from and whether they have been reported before.
Based on these results, I would suggest you keep your wordpress install up to date. Install some plugins to reduce the effectiveness of the attacks.
Watch for unexpected file changes / malicious files
I also suggest making a dummy admin account to catch the bruteforcing there instead of having it spread to your legitimate accounts.