nvidia-smi GPU-Util abnormal

When I run nvidia-smi, it gives:
±-----------------------------------------------------+
| NVIDIA-SMI 340.24 Driver Version: 340.24 |
|-------------------------------±---------------------±---------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute M. |
|===============================+======================+======================|
| 0 Tesla K20m Off | 0000:0A:00.0 Off | 0 |
| N/A 25C P0 49W / 225W | 11MiB / 4799MiB | 0% Default |
±------------------------------±---------------------±---------------------+
| 1 Tesla K20m Off | 0000:0D:00.0 Off | 0 |
| N/A 25C P0 47W / 225W | 11MiB / 4799MiB | 0% Default |
±------------------------------±---------------------±---------------------+
| 2 Tesla K20m Off | 0000:2B:00.0 Off | 0 |
| N/A 27C P0 51W / 225W | 11MiB / 4799MiB | 0% Default |
±------------------------------±---------------------±---------------------+
| 3 Tesla K20m Off | 0000:30:00.0 Off | 0 |
| N/A 28C P0 52W / 225W | 11MiB / 4799MiB | 96% Default |
±------------------------------±---------------------±---------------------+

±----------------------------------------------------------------------------+
| Compute processes: GPU Memory |
| GPU PID Process name Usage |
|=============================================================================|
| No running compute processes found |
±----------------------------------------------------------------------------+

My system is debian and I am not running any job on any of the GPU cards. When is the GPU Util of card 3 not 0%?
Please help!

The act of running nvidia-smi can cause the GPU Utilization number to be non-zero.

Thank you. But is it normal to be as high as 96%?
I ran nvidia-smi in Windows, and it displays all 0%…