More on tomorrow's Harvey argument

One interesting aspect of the Harvey case being argued tomorrow at AFCCA is that it's an Article 69 referral case. While Captain Harvey was sentenced to a dismissal and a reprimand, the convening authority (apparently in an act of pure clemency) disapproved the dismissal. The Judge Advocate General of the Air Force then certified the case to AFCCA pursuant to Article 69(d). One very knowledgable individual tells me that such a referral is extremely rare in the Air Force -- like twice-a-decade rare. How does that compare with the Article 69(d) referral rates in the other services?