Write SQL query to solve given problem: What percentage of games are sports?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(COUNT(CASE WHEN T1.genre_name = 'Sports' THEN T2.id ELSE NULL END) AS REAL) * 100 / COUNT(T2.id) FROM genre AS T1 INNER JOIN game AS T2 ON T1.id = T2.genre_id