High GPU usage with baked lighting

[Alert: Completely beginner in lighting and in any kind of performance optimization]

Update: I did I guess literally nothing that could cause it, just made a few prefabs batching static, and now I have the same performance but the Shadow/depth stuff turned into Others. Earlier, I had the same issue that Others were 90 % of my GPU usage, but it got solved by running build-tests. Now, even if I run build-tests, most of the GPU usage is taken by Others. Cool so, now I really don't know anything about where should I optimize my performance

Hi,
I have a scene with completely baked lighting (okay, my player isn't baked, but that's all the dynamic stuff), but my profiler shows that shadows/depth takes about 90% of GPU usage. How should I resolve it? Or is it normal? If so, please, could someone explain to me how does shadow computing work? (Maybe you are wondering why do I want to optimize my game when I have smooth 60 FPS - well, the map will expand with dynamic elements soon, and also I plan to release the game for a "wider audience", so I can't assume that everyone who will play my game will have a pretty good PC as I have.)
Thank you

 

Hi,
the new category (Others) uses about 14-15 ms. However, I may found the answer to my question. Probably, the Shadows/depth was just a buggy report, it should have gone under Others from the beginning. What I think (or to be more accurate, what someone told me and I agree with that) is that the huge Other GPU usage is because of the VSync. Since my monitor is 60HZ, it just can't go over 60 fps. And maybe it has already got proven since I've added some enemies with animations, navmesh agent and controller and they literally changed nothing on my performance.
Thank you,
Nandu