CREATE TABLE table_66252 ("Class" TEXT, "Wheel arrangement" TEXT, "Fleet number ( s ) " TEXT, "Manufacturer" TEXT, "Serial numbers" TEXT, "Year made" TEXT, "Quantity made" TEXT, "Quantity preserved" TEXT)

What year made has a Quantity made of 4?
SELECT "Year made" FROM table_66252 WHERE "Quantity made" = '4'
SELECT "Year made" FROM "table_66252" WHERE "Quantity made" = '4'