It's not simple. Some countries, like Guatemala, Bolivia and Peru have large populations of almost 100% native Amerindian, or Indigenas, as they prefer to be called, Most others have mestizos, a mix of Spanish/natives. It varies from country to country on how much and to what extent. Counties like Cuba, Puerto Rico and Argentina basically killed off their native populations, either accidentally (through the introduction of diseases like smallpox/tuberculosis/syphilis, which were unknown in the New World so the natives had no immunity) or deliberately (hence the importation of slaves from Spanish/Portuguese colonies in Africa).
There's no real advantage to identifying as a mixed race mutt south of the border so they all downplay their...