select 
    e.emp_no,
    s2.salary - s1.salary as growth
from
    employees e
join salaries s1 on e.emp_no = s1.emp_no 
join salaries s2 on e.emp_no = s2.emp_no
where 
    s1.from_date = e.hire_date and 
    s2.to_date = '9999-01-01'
order by
    growth;