<Tr> <Td> Ahmadreza Rofougaran </Td> <Td> 829 </Td> <Td> USA </Td> <Td> 2002 - 2018 </Td> <Td> Radio Frequency Integrated Circuits </Td> <Td> </Td> </Tr> <Tr> <Td> Nathan Myhrvold </Td> <Td> 786 </Td> <Td> USA </Td> <Td> 1994 - 2018 </Td> <Td> Various </Td> <Td> </Td> </Tr> <Tr> <Td> Jordin T. Kare </Td> <Td> 774 </Td> <Td> USA </Td> <Td> 1992 - 2018 </Td> <Td> Various </Td> <Td> </Td> </Tr> <Tr> <Td> Warren Farnworth </Td> <Td> 772 </Td> <Td> USA </Td> <Td> 1990 - 2017 </Td> <Td> Semiconductor packaging </Td> <Td> </Td> </Tr>

How many inventors are there in the us