Write SQL query to solve given problem: How many percent of countries in North America use English?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(SUM(IIF(T2.Language = 'English', 1, 0)) AS REAL) * 100 / COUNT(T1.Code) FROM Country AS T1 INNER JOIN CountryLanguage AS T2 ON T1.Code = T2.CountryCode