<Table> Launches to Mars <Tr> <Th> Decade </Th> <Th> <Ol> <Li> </Li> </Ol> </Th> </Tr> <Tr> <Th> 1960s </Th> <Td> 13 </Td> </Tr> <Tr> <Th> 1970s </Th> <Td> 11 </Td> </Tr> <Tr> <Th> 1980s </Th> <Td> </Td> </Tr> <Tr> <Th> 1990s </Th> <Td> 8 </Td> </Tr> <Tr> <Th> 2000s </Th> <Td> 8 </Td> </Tr> <Tr> <Th> 2010s </Th> <Td> 5 </Td> </Tr> </Table> <Tr> <Th> Decade </Th> <Th> <Ol> <Li> </Li> </Ol> </Th> </Tr>

How many times have we sent something to mars
find me the text answering this question