CREATE TABLE table_2580 ("No. in series" TEXT, "No. in season" TEXT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( millions ) " TEXT)

How many episodes were listed as number 29 in the series?
SELECT COUNT("No. in season") FROM table_2580 WHERE "No. in series" = '29'
SELECT COUNT("No. in season") FROM "table_2580" WHERE "No. in series" = '29'