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_27155990_1 (_percentage_funded INTEGER, closing_date VARCHAR)

### Question ###
What was the minimum % funded of the project that was closed on 2012-05-18?

### Accurate SQL ###

SELECT MIN(_percentage_funded) FROM table_27155990_1 WHERE closing_date = "2012-05-18"