select tag, concat(round(avg(if(a>1,1,a))*100,2),'%') b
from(
select tag, timestampdiff(second,start_time,end_time)/duration a
from tb_user_video_log left join tb_video_info using(video_id)) as tb1
group by tag
having avg(if(a>1,1,a))>0.6
order by b desc