Does Unity support atomic counter? if does, is there example?

I need to use atomic counter to verify one thing:

Question: Why are vertices processed by vertex shader so few in the Adreno Profiler tool.

Example: I have a mesh with about 818 vertices and 4548 indices. Some part of the mesh is inside of Camera Frustum, and some of the part is behind of other objects.

Result: vertices processed by vertex shader is only 200-300. Make sure that all the 818 vertices are indexed by the 4548 indices.

As I know: all vertices by Indices will be processed by Vertex Shader in the pipeline (Am I wrong ?).

To verify: Is it optimized by Unity, or the result of tool SnapDragon profiler is wrong.