increment / decrement all marked values

[vidret]

Let me just say I *very often* want to mark a couple of values and increment/decrement the marked values.
I very rarely, if ever, need to mark all values.

Maybe the "mark all" could be a different combo. In a year of use I have so far not even tried to find a "mark all" feature but I've instinctively tried to increment/decrement all values because it seems like it should function that way.

If more people could chime in on their usage, I wouldn't want ask to change a function a lot of users are committed to.