disreputable vs unproper

disreputable

adj
  • Not respectable, lacking repute; discreditable. 

noun
  • A person who is not reputable. 

unproper

adj
  • Improper, not according with good standards of behaviour; indecent, indecorous. 

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