http://books.google.co.uk/books?id=6BLqprHdwygC&lpg=PA15...
returns for the most successful railroad companies were mere 5% - competition kept things down (although speculation in early years lead to phenomenal returns - if sold)
However, a moderate VC return is 3fold over ten years - which is ~12.5% YoY (unless my maths is bad). But then that is 12.5% of millions and millions not just one company.