select 
  a.exp_type,
  round(avg(timestampdiff(minute,b.out_time,b.in_time)/60),1) as time
from 
  express_tb as a 
join 
  exp_action_tb as b 
on 
  a.exp_number=b.exp_number
group by 
  a.exp_type
order by 
  time;