<Tr> <Th> Audio format </Th> <Td> Stereo (1989--1991) Dolby Surround 2.0 (1991--2009) Dolby Digital 5.1 (DVD, broadcast 2009--present) </Td> </Tr> <Tr> <Th> Original release </Th> <Td> December 17, 1989 (1989 - 12 - 17)--present </Td> </Tr> <Tr> <Th_colspan="2"> Chronology </Th> </Tr> <Tr> <Th> Preceded by </Th> <Td> The Simpsons shorts from The Tracey Ullman Show </Td> </Tr>

When does season 30 of the simpsons start