<Tr> <Th> 18 </Th> <Td> 35.32 </Td> <Td> George Porter </Td> <Td> United States </Td> <Td> 24 May 1985 </Td> <Td> Norwalk </Td> <Td> </Td> </Tr> <Tr> <Th> 19 </Th> <Td> 35.33 </Td> <Td> Robert Griffin </Td> <Td> United States </Td> <Td> 2007 </Td> <Td> Copperas Cove </Td> <Td> </Td> </Tr> <Tr> <Th> 20 </Th> <Td> 35.34 </Td> <Td> José Bencosme De Leon </Td> <Td> Italy </Td> <Td> 11 September 2016 </Td> <Td> Cuneo </Td> <Td> </Td> </Tr> <Tr> <Th> 21 </Th> <Td> 35.38 </Td> <Td> Ashraf Saber </Td> <Td> Italy </Td> <Td> 22 June 1996 </Td> <Td> Terni </Td> <Td> </Td> </Tr>

How many hurdles are in the 300m hurdles