<Table> <Tr> <Th_colspan="2"> Number of executions </Th> </Tr> <Tr> <Td> 2018 </Td> <Td> </Td> </Tr> <Tr> <Td> 2017 </Td> <Td> 23 </Td> </Tr> <Tr> <Td> 2016 </Td> <Td> 20 </Td> </Tr> <Tr> <Th> Total </Th> <Th> 47 </Th> </Tr> </Table> <Tr> <Th_colspan="2"> Number of executions </Th> </Tr> <Tr> <Td> 2018 </Td> <Td> </Td> </Tr> <Tr> <Td> 2017 </Td> <Td> 23 </Td> </Tr>

When was the last person executed in usa