Restricting dimension

Hi Experts,

I Have one dimension [Defects] it contains all defect codes and not assigned also, Not assigned means no defects.

My requirement is =only defects/total defects(Including no defects)

but in table i have to show only defects and based on above logic, so I am restricting [defects] <>"Not assigned" in variable

when i use this variable in report "Not assigned" showing as null if filtered out null with block level filter the logic is not working.

Could any one help on this.

Thanks,

G Sampath Kumar