<Tr> <Th> 19th </Th> <Th> 1951 </Th> <Td> 28 </Td> <Td_colspan="2"> 26 </Td> <Td> 6 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td_colspan="2"> </Td> <Td> 60 </Td> <Td> Single transferable vote </Td> </Tr> <Tr> <Th> 20th </Th> <Th> 1953 </Th> <Td> 29 </Td> <Td_colspan="2"> 26 </Td> <Td> 5 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td_colspan="2"> </Td> <Td> 60 </Td> <Td> Single transferable vote </Td> </Tr> <Tr> <Th> 21st </Th> <Th> 1955 </Th> <Td> 28 </Td> <Td_colspan="2"> 24 </Td> <Td> 6 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td_colspan="2"> </Td> <Td> 60 </Td> <Td> Single transferable vote </Td> </Tr> <Tr> <Th> 22nd </Th> <Th> 1958 </Th> <Td> 26 </Td> <Td_colspan="2"> 25 </Td> <Td> 7 </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td> </Td> <Td_colspan="2"> </Td> <Td> 60 </Td> <Td> Single transferable vote </Td> </Tr>

Who are the current leaders from each party in the upper house