Query to find skew factor of a particular table?

Query to find skew factor of a particular table?

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;