I was looking the summary of "The Killing Zone" on Amazon today. It said that it's the first 250 hours which are the most dangerous.
I'm sure I've heard elsewhere that it's actually the period between about 200 and 500 hours that sees the most accidents, the reasoning being that for the first couple of hundred hours you realise how little you know and take extra care. After two or three hundred hours you start to think that you've got the hang of it and get complacent.
The second theory actually sounds more convincing. Does anyone know the actual stats?