It's very difficult to quantify, as individual divers may excel at one aspect or another ... but it certainly has nothing to do with number of logged dives. I have logged over 1,200 dives, and have dive buddies with half (or less) of my experience who are better than I am at certain skills.
Some general rules of thumb that may (or not) be applied ...
Beginner - Still working on basic buoyancy skills ... has to keep finning in order to stay off the bottom. Swims in a "fins down" position (to varying degrees) ... typically kicking hard and breathing hard. Has no idea where they're going ... but they're going there pretty darn fast.
Intermediate - Has figured out the basics of buoyancy control ... and breathing control. Can hover without kicking. Has made the mental transition from "vertical" land-based creature to "horizontal" sea-based creature ... and has adjusted their trim accordingly. Is starting to figure out how to find their way around underwater and get back to the entry/exit point with some consistency. Has watched their air consumption rate drop dramatically ... and is starting to figure out that there's way more to diving than their instructor ever told them.
Advanced - Can hover and change depths at will simply by altering their breathing pattern. Has mastered several different fin kicks and applies them according to conditions and situation. Can plan and execute dives in a range of different conditions. Has developed good underwater navigation skills. Understands and applies "situational awareness" at all times during a dive. Can make a mid-water ascent and hold a safety stop without having to hold onto anything.
Those will do for a start ... I'm sure others will add to them ...
... Bob (Grateful Diver)