niqab vs turban

niqab

noun
  • A veil which covers the face, worn by some Muslim women as a part of sartorial hijab. 

turban

noun
  • A man's headdress made by winding a length of cloth round the head. 

  • A woman's close-fitting hat with little or no brim. 

  • The complete set of whorls of a spiral shell. 

How often have the words niqab and turban occurred in a corpus of books? (source: Google Ngram Viewer )