...
Set “0h” Goal to count how long the task was unassigned. Save the configuaration and then you can monitor the time the task was unassigned, which will be calculated in the reverse order (as “-110m, -22m, -1h, -22h, -3h”3h 10m” etc.).
...
The result will be available on the Table grid. And now you can monitor how much time is counted as “Unassigned”.
...