No matter what year we look at, we seem to be running the same trend - more are leaving due to "other reasons" than are leaving due to retirement.
I do not know if this is considered to be a "normal" attrition rate, nor do I know if the percentage of "non-retirement" persons leaving is usually this high. However, it seems that a statistically large number of faculty are leaving for other positions rather than staying and finishing out their careers. At least, this seems true for the years that we have figures for.
It would be interesting to learn just how many of those leaving for other reasons actually based their decision on SFT's regieme. It would also be interesting to learn the number of faculty who took early retirements for the same reason.