<Tr> <Th> Calcium </Th> <Td> (1%) 7 mg </Td> </Tr> <Tr> <Th> Iron </Th> <Td> (2%) 0.24 mg </Td> </Tr> <Tr> <Th> Magnesium </Th> <Td> (3%) 10 mg </Td> </Tr> <Tr> <Th> Manganese </Th> <Td> (2%) 0.038 mg </Td> </Tr>

How many varieties of watermelon are grown in the us