conductivity vs wattage

conductivity

noun
  • The ability of a material to conduct electricity, heat, fluid or sound 

  • The reciprocal of resistivity 

wattage

noun
  • The power requirement of some electric appliance. 

  • An amount or power (especially electric), expressed in watts, kilowatts etc. 

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