Force the phone to turn off (home button + sleep) then reboot and recharge to 100%, this cleared mine the other day. If that doesn't work, try the Reset All Settings option...
its because you did a hard reboot. charge it to about 95-97%, and the stats will/should reset to zero. when you unplug and do a hard reboot, thats when they will change to dashes. if you stop doing that, they should stay and numerical counters.
Like mentioned, I see that when I reset the phone or it crashed. Charging to 100% after that fixes the issue.
Looking at your battery % that might not be the case. You may want to try rebooting/resetting the phone (home + power button until you see Apple logo) then charge it to 100%.