SLC is kind of an odd base in a sense that it's pretty junior to be able to transfer in there, but pretty senior to actually hold a line. There's hardly any movement on both the FO and captain side. There are a lot of super senior FOs in SLC who have upgrade bids just for captain in SLC and no other base. Since there's no movement on the captain side those FOs aren't going anywhere so everything stagnates.

The bottom of the list sees some movement because a lot of the reserve guys transfer around trying to commute to hold lines in different bases. If you want to sit as the plug on reserve in SLC for 3+ years you can get in there, but don't expect a line for a long time.