SELECT usluga, SUM(заявления) as sum
FROM(
SELECT
  COUNT(*)    AS заявления,
  to_char(o.order_date, 'yyyy-mm-dd')                                    AS дата,
  substring(u.title FROM 0 FOR 48)                                       AS оператор,
  o.service_title                         AS usluga
FROM smartcenterorder o, smartcentermfc m, smartcenteruser u
WHERE дата BETWEEN '2016-03-03' AND '2017-03-03'
     AND o.service_title LIKE '%ЕСИА'
GROUP BY оператор, usluga) as foo
GROUP BY usluga
ORDER BY sum desc