1. In the parent case you will find pxCoveredCount which holds the total no. of child cases for the case and pxCoveredCountOpen which holds the total no. of child cases that are not resolved. But with these properties you can only get count of resolved and open cases not the count of each open status or each resolved status
2. If you want a report for each open and resolve statuses then you need to report on child cases. In the child case pxCoverInsKey holds the pzInsKey of the parent case. So can group by using pxCoverInsKey and pyStatusWork to get the desired output. If different child cases are stored on different tables then you might need to join them using pxCoverInsKey and then report on the result set. Consider creating database view also depending upon the data structure.