There have been four voluntary departures out of the eight that you mentioned, so three were let go, and one was dismissed with just cause. Of those eight, one had been employed by the corporation for 13 years and another for 9 years. It's normal. The life cycle of executives in these situations is about four or five years, and the turnover rate is quite comparable with that of other, similar undertakings.
On May 10th, 2012. See this statement in context.