CREATE TABLE table_name_39 (floors INT, name VARCHAR, year VARCHAR)

Name of 900 north michigan, and a Year smaller than 1989 involves what lowest floors?
SELECT MIN(floors) FROM table_name_39 WHERE name = "900 north michigan" AND year < 1989
SELECT MIN("floors") FROM "table_name_39" WHERE "900 north michigan" = "name" AND "year" < 1989