Database: formula_1
Question: Please calculate the race completion percentage of Japanese drivers from 2007 to 2009.
SQL: SELECT CAST(SUM(IIF(T1.time IS NOT NULL, 1, 0)) AS REAL) * 100 / COUNT(T1.raceId) FROM results AS T1 INNER JOIN races AS T2 on T1.raceId = T2.raceId INNER JOIN drivers AS T3 on T1.driverId = T3.driverId WHERE T3.nationality = 'Japanese' AND T2.year BETWEEN 2007 AND 2009