CREATE TABLE table_204_649 (id NUMBER, "rank" NUMBER, "name" CLOB, "image" NUMBER, "height\ ft  ( m ) " CLOB, "floors" NUMBER, "year" NUMBER, "notes" CLOB)

when the key tower was built in 1991 , what was the previous tallest building constructed ?
SELECT "name" FROM table_204_649 WHERE "year" < 1991 ORDER BY "height\nft (m)" DESC LIMIT 1
SELECT "name" FROM "table_204_649" WHERE "year" < 1991 ORDER BY "height\nft (m)" DESC FETCH FIRST 1 ROWS ONLY