<Tr> <Th> Hydrocarbon </Th> <Th> Average </Th> <Th> Range </Th> </Tr> <Tr> <Td> Alkanes (paraffins) </Td> <Td> 30% </Td> <Td> 15 to 60% </Td> </Tr> <Tr> <Td> Naphthenes </Td> <Td> 49% </Td> <Td> 30 to 60% </Td> </Tr> <Tr> <Td> Aromatics </Td> <Td> 15% </Td> <Td> 3 to 30% </Td> </Tr>

Where is the largest amount of petroleum found