Write SQL query to solve given problem: What is the percentage of solutions for the method that needs to be compiled in the English methods?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(SUM(CASE WHEN T1.WasCompiled = 0 THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(Lang) FROM Solution AS T1 INNER JOIN Method AS T2 ON T1.Id = T2.SolutionId WHERE T2.Lang = 'en'