does not show 0fiscper3 key value in xcelcius

Hello all, everything is ok in Bex..it is working well but i dont understand why i couldnt see the 0FISCPER3 key value in my Xcelcius query..i can see text value but not key..

for example;

material sales 0fiscper3 text

x 10 jan

y 20 feb

but if i want to see with key value; doesnt show the key value ..(it should gime 1,2,.....11,12)

material sales 0fiscper3 key

x 10

y 20

any suggestions ?

thanks