This is the A1C/blood glucose chart that my healthcare provider uses. It is the most recent one of know of, being based on a 2008 study.

A1C Chart & Calculator ADAG
A1C-Derived Average Glucose (ADAG)
Study to define the mathematical relationship between HbA1c and eAG.
http://healthy-ojas.com/diabetes/a1c-chart-calculator-adag.html

Translating the A1C Assay Into Estimated Average Glucose Values
Diabetes Care 31:1473–1478, 2008
http://care.diabetesjournals.org/content/diacare/31/8/1473.full.pdf