FR value 
depicts the percentage of the flash wear that has been already used by the camera to save your recording.If you want the FR value reporting the exact flash wear value of the SD Card that you have installed you should change the default value with the value provided by the SD Card manufacturer.
The value in the configuration file that should be edited could be found in:
- Admin Menu–>Configuration–>Edit configuration file (for Experts)
Be carefull what changes you make in this menu. It is a good idea to take a back up of your configuration before you continue.
There find the section fileserver
SECTION fileserver
…MAXIMUM_BLOCK_SWEEPS=2000
…ENDSECTION fileserver
and change the block sweeps value according to your SD Card capabilities.
When you are done press Accept. Now you will be asked if you want to store this settings permanently.
Press Store
and as an security you get asked again if you want to Store Permanently
Settings are saved you should press reboot the camera in order to take effect.
Now the flash wear inforamtion will be more accurate. This info can be found in the camera info menu. either by clicking at the 
button or
http://cam-ip/control/camerainfo
in the section File Server /Flash device.