SELECT MIN("Revenue ($M)") FROM table_15262 WHERE "Country" = 'england' AND "Team" = 'chelsea' AND "Rank" < '7'
Name the least revenue for chelsea of england with rank less than 7
CREATE TABLE table_15262 (
    "Rank" real,
    "Team" text,
    "Country" text,
    "Value ($M)" real,
    "Revenue ($M)" real
)