Database: european_football_2
Question: Calculate the percentage of players who prefer left foot, who were born between 1987 and 1992.
SQL: SELECT CAST(COUNT(CASE WHEN t2.preferred_foot = 'left' THEN t1.id ELSE NULL END) AS REAL) * 100 / COUNT(t1.id) percent FROM Player AS t1 INNER JOIN Player_Attributes AS t2 ON t1.player_api_id = t2.player_api_id WHERE SUBSTR(t1.birthday, 1, 4) BETWEEN '1987' AND '1992'