You can filter the report by status contains "In progress with suspended tasks" and that will show you currently suspended tasks, but it will not show you tasks that have been previously suspended and are not currently suspended. You can set up an email notification for the suspended tasks in the process options, which is probably the easiest option to have a record of suspensions. There may be a way to directly query the Forms SQL database to find events that have been suspended, but I'm not yet familiar with that method.