<Tr> <Td> 2008 </Td> <Td> </Td> <Td> Shanghai World Financial Center, Shanghai </Td> <Td> 2008 </Td> <Td> 474 </Td> <Td> 1,555 </Td> <Td> Two further observation decks at 423 and 439 m (1,388 and 1,440 ft). </Td> </Tr> <Tr> <Td> 2011 </Td> <Td> </Td> <Td> Canton Tower, Guangzhou </Td> <Td> 2011 </Td> <Td> 488 </Td> <Td> 1,601 </Td> <Td> The rooftop outdoor observation deck opened in December 2011 . There are also several other indoor observation decks in the tower, the highest at 433.2 m (1,421 ft). </Td> </Tr> <Tr> <Td> 2014 </Td> <Td> </Td> <Td> Burj Khalifa, Dubai </Td> <Td> </Td> <Td> 555 </Td> <Td> 1,821 </Td> <Td> Opened on October 15, 2014 on the 148th floor . There is another observation deck at 452.1 m (1,483 ft) on the 124th floor, which has been open since the building was opened to the public . </Td> </Tr> <Tr> <Td> 2016 </Td> <Td> present </Td> <Td> Shanghai Tower, Shanghai, China </Td> <Td> 2015 </Td> <Td> 561 </Td> <Td> 1,841 </Td> <Td> Opened on July 1, 2016 . </Td> </Tr>

How much taller is the burj khalifa than the sears tower