yu vs yus

yu

noun
  • The letter Ю, ю. 

  • An ancient Chinese wine-bucket, often having a decorative cover. 

yus

noun
  • Either of two letters, little yus (Ѧ) and big yus (Ѫ), representing nasal vowel sounds in the Cyrillic alphabet. The only major Slavic language retaining these sounds is Polish, which is written in the Latin alphabet. 

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