Shader data path utilization counters

Hi, i'm using streamline to profiler our game's gpu performance. My device is Mali-G77MC9, so i followed this guide: mali-g77-counters.
In "Shader data path utilization" section, i found the "Fragment FPK buffer active percentage" expression gives a high value

Fragment FPK buffer active percentage: 92%

This expression defines the percentage of cycles where the forward pixel kill (FPK) quad buffer, before the execution core, contains at least one quad.
I assume we should keep this percentage as low as possible? Because it indicates we took a lot of shader core power to compute useless Quads. Is this correct?

Execution core utilization：98%

• min(($MaliCoreCyclesExecutionCoreActive / $MaliGPUCyclesGPUActive) * 100, 100)
• min((29.6/30.7)*100,100)=98%

Execution core utilization looks good, because we did have a lot of shader instructions to run.

But i don't understand why Fragment FPK buffer active percentage is so high(92%).

Dose this mean our content takes too much time in FPK Buffer section? Because FPK kills a lot of Quads?

And geometry culling expressions did show there's a lot of geometries are killed by hardware culling unit.

Total input primitives：923K

Total culled primitives：620K

Visible primitives after culling：33%

Facing or XY plane test cull rate：42%

Z plane test cull rate：16%

Sample test cull rate：32%

Does this mean i should do something to lower geometry culling rate, is this related to "Fragment FPK buffer active percentage"?

What should i do to lower "Fragment FPK buffer active percentage"?