SELECT "2-car sets" FROM table_22912 WHERE "Total vehicles" = '622'
Name the 2 car sets for 622
CREATE TABLE table_22912 (
    "Fiscal year" real,
    "2-car sets" real,
    "3-car sets" real,
    "4-car sets" real,
    "6-car sets" real,
    "8-car sets" real,
    "Total vehicles" real
)