Editing Census (section)

===Inca Empire===
In the 15th century, the [[Inca Empire]] had a unique way to record census information. The Incas did not have any written language but recorded information collected during censuses and other numeric information as well as non-numeric data on [[quipus]], strings from [[llama]] or [[alpaca]] hair or cotton cords with numeric and other values encoded by knots in a [[base-10]] positional system.<ref>D'altroy, Terence N. (2001). 154</ref>