select distinct emp_no,growth
from
(select emp_no,
LAST_VALUE(salary)over(partition by emp_no order by from_date range between unbounded preceding and UNBOUNDED following)-first_value(salary)over(partition by emp_no order by from_date range between unbounded preceding and UNBOUNDED following) as growth
from salaries
) t
where (emp_no,'9999-01-01') in (select emp_no,to_date from salaries)
order by growth