CREATE TABLE table_33410 ("Vessel Name" TEXT, "Type" TEXT, "Built" FLOAT, "Class" TEXT, "Flag" TEXT)

Which year was the vessel Deva built as a Panamax DNV class ship?
SELECT SUM("Built") FROM table_33410 WHERE "Class" = 'dnv' AND "Type" = 'panamax' AND "Vessel Name" = 'deva'
SELECT SUM("Built") FROM "table_33410" WHERE "Class" = 'dnv' AND "Type" = 'panamax' AND "Vessel Name" = 'deva'