What is the percentage of Primetime Emmy nominated episodes with a rating over 7 to all the episodes that have a rating over 7?
"Primetime Emmy' is the award_category;  rating over 7 refers to rating > 7; nominated refers to result = 'Nominee'; percentage = Divide(Count(episode_id(award_category = 'Primetime Emmy')), Count (episode_id)) * 100
SELECT CAST(SUM(CASE WHEN T1.award_category = 'Primetime Emmy' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM Award AS T1 INNER JOIN Episode AS T2 ON T1.episode_id = T2.episode_id WHERE T2.rating > 7 AND T1.result = 'Nominee';