Find most used npa/nxx by account
SELECT MAX(add_lskinid) AS 'Account', LEFT(leoutdial,6) AS 'NPA NXX', COUNT(DISTINCT(leoutdial)) AS 'Count'
FROM dnis
WHERE add_lskinid IN ('lskin1','lskin2')
AND lestatus = 1
AND leoutdial NOT LIKE 'v%'
GROUP BY add_lskinid, LEFT(leoutdial,6)
ORDER BY MAX(add_lskinid), 'Count' desc