CREATE TABLE table_16980 ("Total No." FLOAT, "Celebrity" TEXT, "Director" TEXT, "Original air date" TEXT, "Viewers" TEXT)

Which viewers had Matt Gallagher as the director?
SELECT "Viewers" FROM table_16980 WHERE "Director" = 'Matt Gallagher'
SELECT "Viewers" FROM "table_16980" WHERE "Director" = 'Matt Gallagher'