I guess this will help
![Image_ images_messages_5f91c431135b77e2479afee5_bb44adf808ede7958febe1f9f21acd13_10611symgn1_inline-b4afa1db-5816-4a1d-8508-510184df8bd6-162141122.png1479297363 Image_ images_messages_5f91c431135b77e2479afee5_bb44adf808ede7958febe1f9f21acd13_10611symgn1_inline-b4afa1db-5816-4a1d-8508-510184df8bd6-162141122.png1479297363](/t5/image/serverpage/image-id/333iAA8CAF168395C6D5/image-size/large?v=v2&px=999)
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.
So,
SN# 131402013926 was an AP built on work week 13 of 2014.
SN# 161205001992 was an AP built on work week 16 of 2012.
Kind regards
Martin