Table: cougar_town_season2_episodes
Columns: episode_number
episode_name
airdate
viewers_millions
rank_timeslot
rank_18_49_night

Question: what is the total rank on airdate march 30, 2011?
SQL: SELECT COUNT("rank_timeslot") FROM cougar_town_season2_episodes WHERE "airdate" = 'March 30, 2011'