As Robert's link points out, the difference is well within the normal lab variation.
I suspect you are asking questions that no-one really knows the answer to. The other day I found a paper suggesting that high glucose kills off red blood cells. Today, I found this one where they found exactly the opposite
In this study, the DM subjects with the poorer glycemic control had the higher mean RBC ages, arguing against an effect of poor glycemic control on RBC survival.These results differ from 2 previous reports but agree with others.'
http://www.bloodjournal.org/content/bloodjournal/112/10/4284.full.pdf?sso-checked=true
How much does it really matter? You know what your levels are and they aren't very high.
These figures from a presentation about HbA1c controversies (Kilpatrick) puts things into perspective.
If someone aged 46 is diagnosed with diabetes tomorrow, at what age on average, will they develop retinopathy? (ie serious as it comes from the progression stats in the DCCT)
at an HbA1c of 12%? 51 years.
at an HbA1c of 9% ? 61 years
at an HbA1c of 7% ? 98 years
at an HbA1c of 6%? 154 years
http://www.york.ac.uk/media/healthsciences/documents/events/diabetesconference2011/Eric%20Kilpatrick%20HbA1c%20controversies.pdf
Hopefully, ,I won't be around to find out if I'm average or not!