Write SQL query to solve given problem: What percentage of matches played on 2005/07/30 belong to the F1 division?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(SUM(CASE WHEN Div = 'F1' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(Div) FROM matchs WHERE Date = '2005-07-30' 