<Tr> <Td> 11770 </Td> <Td> D - 131 </Td> <Td> </Td> <Td> 2002 </Td> <Td> 99 t </Td> <Td> Caspian Flotilla </Td> <Td> </Td> </Tr> <Tr> <Td> 11770 </Td> <Td> D - 56 </Td> <Td> </Td> <Td> 2005 </Td> <Td> 99 t </Td> <Td> Caspian Flotilla </Td> <Td> </Td> </Tr> <Tr> <Td> 11770 </Td> <Td> D - 172 </Td> <Td> </Td> <Td> 2005 </Td> <Td> 99 t </Td> <Td> Caspian Flotilla </Td> <Td> </Td> </Tr> <Tr> <Td> 11770 </Td> <Td> D - 144 </Td> <Td> </Td> <Td> 2008 </Td> <Td> 99 t </Td> <Td> Black Sea Fleet </Td> <Td> </Td> </Tr>

How many ships are in the russian navy