<Tr> <Th> 1970 </Th> <Td> 3,500 </Td> </Tr> <Tr> <Th> </Th> <Td> 1,500 </Td> </Tr> <Tr> <Th> </Th> <Td> 6,500 </Td> </Tr> <Tr> <Th> 1979 </Th> <Td> 10,000 </Td> </Tr>

Which statement describes the long-term trend for political parties in the united states