select i, coalesce(lpad('*', count(s), '*'), ' ') from ( select trunc(salary, -3) s from employees ) stat right join (select level*1000 i from dual connect by level <= 25) r on r.i = stat.s group by i order by i resultat: 1000 2000 ************************ 3000 ****************** 4000 ******* 5000 * 6000 ********** 7000 *********** 8000 ********* 9000 ******** 10000 ****** 11000 **** 12000 *** 13000 ** 14000 * 15000 16000 17000 ** 18000 19000 20000 21000 22000 23000 24000 * 25000