CREATE TABLE table_4459 ("Episode #" FLOAT, "Title" TEXT, "Air Date" TEXT, "Demo" TEXT, "Viewers" TEXT)

When is the air date that demo-ed at 1.6/5?
SELECT "Air Date" FROM table_4459 WHERE "Demo" = '1.6/5'
SELECT "Air Date" FROM "table_4459" WHERE "Demo" = '1.6/5'