Skewness value doesn't display until one dimension value is selected

[nguyvie]

Hi everyone. The app I'm currently developed has a chart  with measure as turnover and dimension as age_group (display in the bottom below). We tried to calculate the skewness of the chart (turnover and age_group) over the another dimension, in this case department_name.  I also create a table (on top right, with dimension as department_name, measure as skewness) to display the skewness  over different departments 

Skewness formula:  =Skew( Aggr( sum( turnover), age_group))

doesn't display

For some reason, the  skewness value in the table doesn't get displayed (grey color with  hyphen -), until one specific department is selected (picture below)

Is there anyway to display  all the skewness for each department like in the first picture (so that the user can see all of the skewness instead of having to select each department to see skewness value)?