<Tr> <Td> 17 </Td> <Td> SRB </Td> <Td> Ana Ivanovic (1) </Td> <Td> Jun 9, 2008 </Td> <Td> Aug 10, 2008 </Td> <Td> 9 </Td> <Td> 9 </Td> </Tr> <Tr> <Td> 18 </Td> <Td> SRB </Td> <Td> Jelena Janković (1) </Td> <Td> Aug 11, 2008 </Td> <Td> Aug 17, 2008 </Td> <Td> </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> SRB </Td> <Td> Ana Ivanovic (2) </Td> <Td> Aug 18, 2008 </Td> <Td> Sep 7, 2008 </Td> <Td> </Td> <Td> 12 </Td> </Tr> <Tr> <Td> </Td> <Td> USA </Td> <Td> Serena Williams (2) </Td> <Td> Sep 8, 2008 </Td> <Td> Oct 5, 2008 </Td> <Td> </Td> <Td> 61 </Td> </Tr>

Who is ranked number 1 in womens tennis