<Table> <Tr> <Th> Season </Th> <Th> Time slot (ET) </Th> <Th> Rank </Th> <Th> Rating </Th> </Tr> <Tr> <Td> 1976 - 1977 </Td> <Td> Thursday at 8: 30 - 9: 00 PM (Episodes 1 - 4, 10 - 21) Saturday at 8: 30 - 9: 00 PM (Episodes 5 - 9) </Td> <Td> 25 </Td> <Td> 20.9 </Td> </Tr> <Tr> <Td> 1977 - 1978 </Td> <Td> Thursday at 8: 30 - 9: 00 PM (Episodes 1 - 15, 22) Saturday at 8: 00 - 8: 30 PM (Episodes 16 - 20) Thursday at 8: 00 - 8: 30 PM (Episode 21) </Td> <Td> 42 </Td> <Td> N / A (Tied with Dallas and The Rockford Files) </Td> </Tr> <Tr> <Td> 1978 - 1979 </Td> <Td> Thursday at 8: 30 - 9: 00 PM (Episodes 1 - 12) Friday at 8: 30 - 9: 00 PM (Episodes 13 - 18) Saturday at 8: 00 - 8: 30 PM (Episodes 19 - 22) </Td> <Td> 28 </Td> <Td> 19.8 (Tied with Monday Night Football) </Td> </Tr> </Table> <Tr> <Th> Season </Th> <Th> Time slot (ET) </Th> <Th> Rank </Th> <Th> Rating </Th> </Tr> <Tr> <Td> 1976 - 1977 </Td> <Td> Thursday at 8: 30 - 9: 00 PM (Episodes 1 - 4, 10 - 21) Saturday at 8: 30 - 9: 00 PM (Episodes 5 - 9) </Td> <Td> 25 </Td> <Td> 20.9 </Td> </Tr> <Tr> <Td> 1977 - 1978 </Td> <Td> Thursday at 8: 30 - 9: 00 PM (Episodes 1 - 15, 22) Saturday at 8: 00 - 8: 30 PM (Episodes 16 - 20) Thursday at 8: 00 - 8: 30 PM (Episode 21) </Td> <Td> 42 </Td> <Td> N / A (Tied with Dallas and The Rockford Files) </Td> </Tr>

Where is the crew from what's happening