It used to be automatic, up a level every year of service. Now it's dependant on your 'work performance' i.e. how many sick days you take.
Journeymen controllers are being pushed onto training on the next sector on their group before they have had proper consolidation or are ready to do so. This is due to serious staffing problems on most groups. You'd think in return for achieving extra ratings that you'd skip a level or two.................not likely.
In rare cases you may advance two levels in one go, but I mean rare. You would have to do some serious ar$e licking to achieve that.