<Table> Ski cross <Tr> <Td_colspan="2"> Ski Cross competitors navigating a jump during January 2010 World Cup competitions in Les Contamines - Montjoie, France </Td> </Tr> <Tr> <Th> Highest governing body </Th> <Td> International Ski Federation </Td> </Tr> <Tr> <Th> Nicknames </Th> <Td> Skier Cross, Skier - X </Td> </Tr> <Tr> <Th_colspan="2"> Characteristics </Th> </Tr> <Tr> <Th> Contact </Th> <Td> No </Td> </Tr> <Tr> <Th> Team members </Th> <Td> Single competitors </Td> </Tr> <Tr> <Th> Mixed gender </Th> <Td> Yes </Td> </Tr> <Tr> <Th> Type </Th> <Td> Freestyle skiing </Td> </Tr> <Tr> <Th_colspan="2"> Presence </Th> </Tr> <Tr> <Th> Olympic </Th> <Td> 2010, 2014, 2018 </Td> </Tr> </Table> <Tr> <Td_colspan="2"> Ski Cross competitors navigating a jump during January 2010 World Cup competitions in Les Contamines - Montjoie, France </Td> </Tr>

When was ski cross added to the olympics
find me the text answering this question