How to create a report to show date difference between the RITM open state to In progress state

Hi all,

we need to create a report that show  how many days it has been taken for RITM to move from opened STATE to In progress state and in progress state to approval state    and then approval state to rejected state we need to show how many days taken to RITM move from one state to another for all state from opened to completed.

We need the show the days count in report

can anyone help me on this.

Thanks,