These numbers don't mean anything anymore. Remember Illustrator 88? Or Microsoft's switch from version numbers (Windows 3.1, 3.11, 3.2) to years (Windows 95, 95 A, 95 B, OSR 2.5) to years with Service Packs (Win2k SP4) and then back to version numbers (7, 8) first with service packs (7 SP1) and then version numbers? (8.1)
We're full circle from insanity to worse, and it only took 20 years!
OS X 10.9.2 includes Darwin Kernel 13.1.0 and XNU 2422.92.1. FWIW.
And don't even get me started on build numbers. (13C1021? The hell is that? Why would you even leave a number like that in a customer-accessible location?)