Problème de datation

YYMMFFXXXXX

YY year
MM month
FF factory-code
XXXXX production#

FACTORY NUMBER CODES -- for some models starting in 2008, if serial # begins w/numbers
[NOTE: The factories identified by these codes are based on patterns which forum members have observed. The numbers appear as the 5th and sixth digits in the serial number.]
11 = MIC sticker on a '08 Masterbuilt
12 = DeaWon or Unsung (China -- uncertainty remains as to which factory)
15 = Qingdao (China) -- electric
16 = Qingdao (China) -- acoustic
17 = China - factory unknown MIC sticker on a J160E
18 = China - factory unknown found on one 2009 model bass
20 = DaeWon or Unsung (China -- uncertainty remains as to which factory)
21 = Unsung, Korea
22 = ??? Korea (factory still unknown)
23 = ??? Indonesia (factory still unknown, probably Samick,)
I = Indonesia (this letter has appeared as the 5th digit on two authentic new models made in Indonesia