CREATE TABLE table_13346 ("Class to 1928" TEXT, "Class from 1928" TEXT, "Seats" TEXT, "Quantity" FLOAT, "Year ( s )  of Manufacture" TEXT)

What's the sum of Quantity for the Class of 1928 of CI-30?
SELECT SUM("Quantity") FROM table_13346 WHERE "Class from 1928" = 'ci-30'
SELECT SUM("Quantity") FROM "table_13346" WHERE "Class from 1928" = 'ci-30'