Do you mean you need to figure out the percentages?
%Fail
SUM(iif(Fields!Test.value="Fail", 1, 0)) / Count(Fields!Test.value)
%Pass
SUM(iif(Fields!Test.value="Pass", 1, 0)) / Count(Fields!Test.value)
Fail/Pass
iif(SUM(iif(Fields!Test.value="Pass", 1, 0)) <> 0, SUM(iif(Fields!Test.value="Fail", 1, 0)) / SUM(iif(Fields!Test.value="Pass", 1, 0)), 0)