how to calculate top 20% and bottom 20% difference

[Naveen Tibco]

Hello folks,

 

i have "ID" and "value" columns.

1) i did order as "decending order"

--> how to calculate top 20% and bottom 20%

--> how to calculate difference between top 20% and bottom 20% value.

 

for reference i shared attachment..

 

Regards

Naveen

 

 

Thanks & Regards

Nagaraju