SELECT MIN("Sales (billion $)") FROM table_49592 WHERE "Company" = 'bp'
What is BP's lowest sales?
CREATE TABLE table_49592 (
    "Rank" real,
    "Company" text,
    "Country" text,
    "Industry" text,
    "Sales (billion $)" real,
    "Profits (billion $)" real,
    "Assets (billion $)" real,
    "Market Value (billion $)" real
)