CREATE TABLE table_name_17 (number_of_deputies INTEGER, number_of_votes_received VARCHAR, election_date VARCHAR)
What was deputies with the lowest number of unknown received votes, in an election year after 1986?
SELECT MIN(number_of_deputies) FROM table_name_17 WHERE number_of_votes_received = "unknown" AND election_date > 1986
SELECT number_of_deputies FROM table_name_17 WHERE number_of_votes_received = 'unknown' AND CAST(SUBSTR(election_date, 1, 4) AS INTEGER) > 1986 ORDER BY number_of_deputies ASC LIMIT 1;