Custom report to check is incident has been postponed

Dear Team,

I am new to create the customized reports.

We have added a custom field for Incident called "Delivery Package" where we define the releases in which bug will be delivered. Now, I have to create a report that will fetch all the incidents which have been postponed to next release (by checking delivery package).

I have the logic. I should check at the time of creation if value for "Delivery Package" is not same as current value then it means it has been postponed. But I am not sure what the query will be.

Please assist.

Thanks!