Query to find SKEW FACTOR of a particular table in Teradata

SELECT 
TABLENAME,
SUM(CURRENTPERM) /(1024*1024) AS CURRENTPERM, 
(100 - (AVG(CURRENTPERM)/MAX(CURRENTPERM)*100)) AS SKEWFACTOR 
FROM 
DBC.TABLESIZE 
WHERE DATABASENAME= <DATABASENAME> 
AND 
TABLENAME =<TABLENAME>  
GROUP BY 1;