, I think more than 5-10% would hit their target,
Entirely dependent upon many factors to generalize.. everything from the period you're referring to; the particular night; the particular target; the weather/cloud cover: whether there were a single, double or triple stream, with false targets being approached: Master Bombers: what technology was used and available at that particular time: the number of aircraft: what target marking was used on the night. If you want a good picture - get a copy of Len Deighton's "Bomber". It is the story of a single night's raid on Krefeld, in the Ruhr: the short prelude and the aftermath, told from both sides. "Deighton's cool, merciless, detailed reconstruction of the raid is overwhelming. The reader is denied the protection of distance or ignorance" (partial cover quote).
This book will give one the real sense of being in a war.
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