create a formula like;
shared numbervar assigned;
shared numbervar unassigned;
if isnull({table.departmentID}) then
unassigned := unassigned + 1;
else
assigned := assigned + 1;
suppress the detail section, and place the formula in the detail section
in the report footer add 2 labels, on for assigned and one for unassigned (as in example) then create 2 formula and place them next to the desired labels.
one formula will look like:
shared numbervar assigned
and the other:
shared numbervar unassigned
HTH
in the non-suppressed section put a