What is the percentage of people who gave the "True North" episode a 1-star rating?
the "True North" episode refers to title = 'True North'; 1-star refers to stars = 1; percentage = divide(count(episode_id where stars = 1), count(episode_id)) * 100% where title = 'True North'
SELECT CAST(SUM(CASE WHEN T2.stars = 1 THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(T1.episode_id) FROM Episode AS T1 INNER JOIN Vote AS T2 ON T1.episode_id = T2.episode_id WHERE T1.title = 'True North' AND T1.episode_id = 'tt0629477'