Year and Serial don't add up?

[swetzel]

I have a 2012 Suntracker Partybarge with a 90hp 2-stroke
90ELPTO
Serial 1B884196
Date Sticker says 2011

I see parts for it from 2005 and 2006, is this an older made engine but not put into service until 2011?

Thanks

[boats.net]

That serial number is a 90ELPTO DFI SW model number 1090D73HY manufactured in 2011,
Parts catalog: 90 DFI (3 CYL.)(1.5L) 1B736885 & Up Mercury Outboard Parts