year(EpisodeDate) AS [Year],
count(*) AS [Number of episodes]
FROM tblEpisodeEnemy ee INNER JOIN tblEnemy e
ON ee.EnemyId = e.EnemyId INNER JOIN tblEpisode ep
ON ep.EpisodeId = ee.EpisodeId INNER JOIN tblDoctor d
ON ep.DoctorId = d.DoctorId
WHERE year(BirthDate) < 1970
GROUP BY year(EpisodeDate) ,EnemyName