CREATE TABLE table_51104 ("Owner" TEXT, "Class" TEXT, "Number in class" FLOAT, "Road numbers" TEXT, "Built" TEXT)

What was built in a class with less than 10, and the Downer Rail owner?
SELECT "Built" FROM table_51104 WHERE "Number in class" < '10' AND "Owner" = 'downer rail'
SELECT "Built" FROM "table_51104" WHERE "Number in class" < '10' AND "Owner" = 'downer rail'