Im thinking that there were more persons of native american ancestry than what was recorded back in those days. But it probarly would be VERY difficult to find out exactly how many due to the types of racial labels that were given to people of mixed ancestry. I saw an entire group of people who were part of a native american reservation in Louisiana listed as being "mulatto" by the census enumerator in Louisiana(1850-1870). From what I knew about these families, they were a mixture of native american and europeon with a small degree of african ancestry going back into the 18th century. Many of their descendents identify as Black, Native american, and white. Its similar to all of the families on Paul Heineggs website in origin.
Rodney Sam