bluntforce - 7:27 am on Feb 3, 2013 (gmt 0)
Why the removal of keyword heavy anchor text?
You state gradual decline, not an event. So why did you decide that removing anchor text was the solution to a gradual traffic decline?
If you think there's a filter/penalty issue, changing anchor text is perhaps understandable. De-optimizing something that isn't over-optimized really is an exercise in futility.