Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_17 (number_of_deputies INTEGER, number_of_votes_received VARCHAR, election_date VARCHAR)

### Question ###
What was deputies with the lowest number of unknown received votes, in an election year after 1986?

### Accurate SQL ###

SELECT MIN(number_of_deputies) FROM table_name_17 WHERE number_of_votes_received = "unknown" AND election_date > 1986