<Tr> <Td> U.S. 29 </Td> <Td> Pensacola </Td> </Tr> <Tr> <Td> U.S. 41 </Td> <Td> Bradenton, Fort Myers, Naples, St. Petersburg, Tampa </Td> </Tr> <Tr> <Td> U.S. 49 </Td> <Td> Biloxi, Gulfport </Td> </Tr> <Tr> <Td> U.S. 59 </Td> <Td> Houston, Victoria </Td> </Tr>

What is the population of the coastal plain region in texas