select (select sum(rashody) from transport_reestr where transport_type=‘taxi’)/ sum(rashody) from transport_reestr
SELECT (SELECT SUM (RASHODY)
FROM TRANSPORT_REESTR
WHERE TRANSPORT_TYPE = 'TAXI') / SUM (RASHODY)
FROM TRANSPORT_REESTR
GROUP BY НАЗВАНИЕ_ПОЛЯ;
SELECT (SELECT SUM (RASHODY)
FROM TRANSPORT_REESTR
WHERE TRANSPORT_TYPE = 'TAXI') /
(SELECT SUM (RASHODY)
FROM TRANSPORT_REESTR)
FROM DUAL;