Most of Amazon's employee base are in the warehouses, and there's a significant amount of churn there, especially seasonal. Being median at 11 months is really not that weird considering the sheer nature of warehouse employment there, and considering it's highly likely you were there through at least one Q4.
The tool in Amazon that shows how your tenure ranks is measured against _all_ Amazon employees. Warehouse, delivery, etc.
I was well past the 60% mark by the time I got through my first Q4 working for Amazon as an SE, and in to something like 90% by the time I got through my second. The figures the L7 engineers were bouncing around at that time were that developers averaged around 2 years.
