I guess this will help
Work Week 1 - 9, first digit will use a 9 to avoid a leading zero. For example 92 represents the 2nd work week.
For a 2 digit Year code: we allow 0, for example 09 is 2009.
SN# 131402013926 was an AP built on work week 13 of 2014.
SN# 161205001992 was an AP built on work week 16 of 2012.