mysql, Getting Top N Percentage

SELECT*
FROM    (
    SELECT TB_MUSIC_VIDEO.*, @counter := @counter +1 AS counter
    FROM (select @counter:=0) AS initVar, TB_MUSIC_VIDEO

    ORDER BY rating_count DESC   
) AS X
where counter <= (10/100 * @counter);
ORDER BY rating_count DESC

ref. http://stackoverflow.com/questions/5615172/mysql-limit-by-a-percentage-of-the-amount-of-records