Question: Among the games published by Nintendo, what is the percentage of those in the genre of sports?
SQL: SELECT CAST(COUNT(CASE WHEN T4.genre_name = 'Sports' THEN T1.id ELSE NULL END) AS REAL) * 100/ COUNT(T1.id) FROM game AS T1 INNER JOIN game_publisher AS T2 ON T1.id = T2.game_id INNER JOIN publisher AS T3 ON T2.publisher_id = T3.id INNER JOIN genre AS T4 ON T1.genre_id = T4.id WHERE T3.publisher_name = 'Nintendo'