<Tr> <Td> Swimming and diving </Td> <Td> 7 </Td> <Td> 8 </Td> </Tr> <Tr> <Td> Squash </Td> <Td> 8 </Td> <Td> 8 </Td> </Tr> <Tr> <Td> Tennis </Td> <Td> 8 </Td> <Td> 8 </Td> </Tr> <Tr> <Td> Track and field (indoor) </Td> <Td> 8 </Td> <Td> 8 </Td> </Tr>

When did university of pennsylvania became ivy league