Write SQL query to solve given problem: What's the home win ratio of the Bundesliga division in 2021?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(COUNT(CASE WHEN T1.FTR = 'H' THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(T1.FTR) FROM matchs AS T1 INNER JOIN divisions AS T2 ON T1.Div = T2.division WHERE T1.season = 2021 AND T2.name = 'Bundesliga'