What is the percentage of the podcast that are categorized in four or more categories?
categorized in 4 or more refers to Count(category) > 4; percentage = Divide(Count(podcast_id(count(category) > 4)), Count(podcast_id)) * 100
SELECT COUNT(T1.podcast_id) FROM ( SELECT podcast_id FROM categories GROUP BY podcast_id HAVING COUNT(category) >= 4 ) AS T1