The disk occupancy can go as high as 100% before the auto-cleaning starts to free space.
Auto-cleaning is automatically enabled when the disk occupancy reaches 95%. However, it may not run immediately if your system is busy recording calls. It will wait for a ‘quiet’ period, when there are no recordings in progress to run. As a result, you may see disk occupancy of more than 95%.
Obviously if there is no ‘quiet’ period as the disk occupancy reaches 100%, the auto-clean will run even if recordings are in progress.