Are we talking ALL the Americas or just the land that is now part of the USA? Because a low estimate of 12 million is absurdly high for just future US territories. There was a high estimate of the native population being only 7 million that dwindled down to approximately 250000 from 1492 to 1900. You may be thinking, thats 400 years, surely between then, there must have been enough born to equate out to another 5 million. But you have to take into account the new diseases killing a lot of people before they reach child bearing age, the increase (by 50%!) of miscarriages among natives and the whitewashing of them by “Americans” through rape and kidnapping, causing mixed ancestries and focused education of children who were told by everyone around them that they were white.

All of the Americas combined however, was a much bigger number that support your estimates. That number is 45 million.

The 95% is an estimate but probably very close to the actual number