Maybe you guys can help me understand this?

I photoshoped the lines in for reference from my dyno yesterday. But it seems that the only time that I go over 14 AFR is from 4600 RPM to 5600RPM. Should I be near a constant 13:1 AFR at all times or what on a N/A engine? Or do I risk detonation and engine knock if I leave it as is? I'm a newb when it comes to tuning...