CREATE TABLE table_63851 ("Airline" TEXT, "IATA" TEXT, "ICAO" TEXT, "Callsign" TEXT, "Commenced operations" FLOAT)

Which Commenced operations have an Airline of valuair?
SELECT MAX("Commenced operations") FROM table_63851 WHERE "Airline" = 'valuair'
SELECT MAX("Commenced operations") FROM "table_63851" WHERE "Airline" = 'valuair'