Simplify the following text for a Grade 8 native English-speaking person.
Original: In addition to operating one of the largest domestic route networks in the U.S. , Northwest carried more passengers across the Pacific Ocean ( in 2004 ) than any other U.S. carrier , and carried more domestic air cargo than any other American passenger airline .
Simplified: In addition to operating one of the largest domestic route networks in the U.S. , Northwest carries more passengers across the Pacific Ocean ( 5.1 million in 2004 ) than any other U.S. carrier , and carries more domestic air cargo than any other American passenger airline .