<Tr> <Th> Location </Th> <Td> Montreal </Td> </Tr> <Tr> <Th> Effective </Th> <Td> 1 January 1989 if 11 states have ratified by then . </Td> </Tr> <Tr> <Th> Condition </Th> <Td> ratification by 20 states </Td> </Tr> <Tr> <Th> Signatories </Th> <Td> 46 </Td> </Tr>

Where did the 1987 meeting that limited use of chlorofluorocarbons take place