user: Question: How many seasons was the rank equal to #50?
Columns: ['Season', 'Episodes', 'Timeslot ( ET )', 'Season premiere', 'Season finale', 'TV season', 'Rank', 'Viewers (in millions)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 22.0, 'Tuesday 8:00pm (2005) Wednesday 8:00pm (2006)', 'September 13, 2005', 'May 17, 2006', '2005–06', '#60', '8.90']
SQL:

assistant: SELECT COUNT("Season") FROM "Table" WHERE "Rank" = '#50';