From the source...
 

Been a member of APC for a long time but rarely post.

Regarding seniority projections. I took my oldest list, January of 1996, and projected a pilot through his career, then checked where he was and re-started the projection at various points.

Note that his ORIGINAL projection, in brown, is buried under the orange line. The big difference can be almost entirely explained by age 65.

The issue is, as early retirements see pilots leave early, it sucks the future retirements dry. If 10 pilots senior to him retire early in a given year, that's 10 fewer pilots that retire on time in subsequent years.

Curly

http://widgetseniority.com/images/mc...dvancement.png