<Tr> <Td> Condor </Td> <Td> 1988 </Td> <Td> 1990 </Td> <Td> Flat Ride </Td> <Td> </Td> </Tr> <Tr> <Td> Swiss Bob </Td> <Td> </Td> <Td> 1991 </Td> <Td> Flat Ride </Td> <Td> </Td> </Tr> <Tr> <Td> Lightnin' Loops </Td> <Td> 1978 </Td> <Td> 1992 </Td> <Td> Roller Coaster </Td> <Td> A roller coaster where one track was sent to Adventure World (now named Six Flags America) while the other was moved to Frontier City . </Td> </Tr> <Tr> <Td> Shockwave </Td> <Td> 1990 </Td> <Td> 1992 </Td> <Td> Roller Coaster </Td> <Td> Was moved to Six Flags Astroworld . </Td> </Tr>

How long is a season at six flags