Their section about demographics controls in the paper was really unclear (kinda surprised you can get this published being so vague). What does a final number

Their section about demographics controls in the paper was really unclear (kinda surprised you can get this published being so vague). What does a final number with the controls active even mean? I doubt accuracy was identical within each grouping they used. Even the groupings are really unclear in the paper (at most 4 ethnic groups，no idea how they did age, etc.)