Some historians believe that up to what percentage of new word population was killed

90%

When the Europeans arrived, carrying germs which thrived in dense, semi-urban populations, the indigenous people of the Americas were effectively doomed. They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans.

Explanation:

it was the "4. potsdam" conference that demanded the unconditional surrender of japan, since it was clear that the japanese would continue to find until the very last man otherwise.

(1)representation based on state population (2)all states have equal representation apex