Database: formula_1
Question: From 2000 to 2005, what percentage of drivers who were born before 1985 and the lap numbers were over 50?
SQL: SELECT CAST(SUM(IIF(STRFTIME('%Y', T3.dob) < '1985' AND T1.laps > 50, 1, 0)) AS REAL) * 100 / COUNT(*) 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 T2.year BETWEEN 2000 AND 2005