mobility vs travelling

mobility

noun
  • The ability to move; capacity for movement. 

  • A tendency to sudden change; mutability, changeableness. 

  • The degree to which particles of a liquid or gas are in movement. 

  • People's ability to move between different social levels or professional occupations. 

  • The ability of a military unit to move or be transported to a new position. 

travelling

noun
  • The act of one who travels; a journey. 

adj
  • That travels (with one) 

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