Good question. The reason there is a “-” under the jumping abilities frame data and a number under the st/cr ones is simple: You cannot block or continue a string of attacks in the air. Frame data applies to all moves in the game, but since there is no way you can block a move in the air, there is no point in having a figure that represents how quickly you recover after you hit somebody.
Think about it like this: When you attack somebody on the ground, if you hit them, you have recovery frames for who has frame advantage. The same applies to blocking. This determines how quickly you are able to execute your next move before your opponent can. However, in the air, there’s only 2 things that can happen:
- 1 move beats another or
- both moves trade
You cannot execute another move in the air after you do one (unless you jump again), so it does not make sense to have frame advantage/disadvantage on jumping moves. You can’t block in the air, so there is no advantage/disadvantage.
So in short, you do not need to know the advantage that jumping HK has on hit because, if it hits, it resets the other opponent until you both land. Both players are completely even on frames upon landing.