115 and 116 are 051C, and the never used 114, I suspect is for an aborted 051B, that was supposed to be the twin for 167 Shenzhen.
I can see 055 take over from 109 to 114, but I don't know if 115 and 116 will be scrapped soon as they are relatively newer ships, newer than the 051B, 052B, and two of the Project 956. Having said that, how they will MLU the two 051C remains unclear.
There are also pennant ranges that are empty, such as 14X, 18X and 19X.
With the way 055s pennants numbers are going, it makes it inherently difficult to track 055s potential fleet basing. Before, I realized that 101-129 numbers belong to North Sea Fleet, 130-159 to the ESF, and 160-199 to SSF. But now it's hard to tell with Type-055 #105 going to SSF.
Maybe the basing for 105-108 to the SSF are temporary, like PLAN just wants 4 055s for each 1 carrier. And since CV-17 might be going to SSF, they wanted 4 055s with her. Just like 4 055s with CV-16 in the NSF, for which their pennants (101-104) makes sense.
It's quite possible to attach current 055s numbers to carriers; essentially 4 055s for each carrier. And with the rumored 8 more being ordered (4 for Type-003/CV-18 and 4 more for the next Type-003/CV-19).
It's possible once those 8 055s and more are built, they will be a re-shuffle of ships with 105-108 joining the NSF and maybe the new ones taking appropriate pennant #s. I always had assumed new Destroyer squadrons would be created with 055s and 052Es filling 14x, 18x, and 19x pennant #s. And maybe PLAN creating another Destroyer squadrons with just 101-109/110 filled with 055s. destroyers.
This is all just pure speculation on my part.