Input (grade 13): At some battles, such as at Iwo Jima, there had been no civilians involved, but Okinawa had a large indigenous civilian population and, according to various estimates, somewhere between 1/10 and 1/3 of them died during the battle.
Output (grade 10): At some battles, such as Iwo Jima, there had been no civilians, but Okinawa had a lot of civilian population.