What was deputies with the lowest number of unknown received votes, in an election year after 1986?
CREATE TABLE table_6218 (
    "Election date" real,
    "Party leader" text,
    "Number of votes received" text,
    "Percentage of votes" text,
    "Number of deputies" real
)
SELECT MIN("Number of deputies") FROM table_6218 WHERE "Number of votes received" = 'unknown' AND "Election date" > '1986'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What was deputies with the lowest number of unknown received votes, in an election year after 1986? ### Input: CREATE TABLE table_6218 (
    "Election date" real,
    "Party leader" text,
    "Number of votes received" text,
    "Percentage of votes" text,
    "Number of deputies" real
) ### Response: SELECT MIN("Number of deputies") FROM table_6218 WHERE "Number of votes received" = 'unknown' AND "Election date" > '1986'