What's the home win ratio of the Bundesliga division in 2021?
home win refers to FTR = 'H', where H stands for home victory; season = '2021'; Bundesliga is a name of division; DIVIDE(COUNT(Div where FTR = 'H, season = '2021' and name = 'Bundesliga'), COUNT(Div where season = '2021' and name = 'Bundesliga')) as percentage;
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'