The baseline 747-400 delivers more range, better fuel economy, lower noise and lower operating costs than previous 747 models. The 747-400 has a range of approximately 7,260 nautical miles (13,450 km), and the lowest cost per seat-mile of any twin-aisle airplane in service today. It has a dispatch-reliability rate of nearly 99 percent. Boeing delivered the first 747-400 in 1989 to Northwest Airlines. Since the first 747 delivery in 1969, Boeing has delivered 1,370 747s.