alleviation vs attenuation

alleviation

noun
  • the act of reducing pain or anything else unpleasant; easement 

  • the act of alleviating; relief or mitigation. 

attenuation

noun
  • The reduction of the active principles of medicines to minute doses. 

  • A reduction in the level of some property with distance, especially the amplitude of a wave or the strength of a signal. 

  • The tapering of a leaf etc to a fine point. 

  • A weakening in the virulence of a pathogen or other microorganism. 

  • A fabrication process in which a material is stretched out into a thin shape. 

  • The proportion of sugar that is converted to ethanol by a yeast. 

  • A gradual diminishing of strength. 

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