variability vs wiggle room

variability

noun
  • The state or characteristic of being variable. 

  • The degree to which a thing is variable. In data or statistics this is often a measurement of distance from the mean or a description of data range. 

wiggle room

noun
  • The opportunity to make alternative decisions or to pursue other courses of action, especially any involving only minor changes to one's present situation or course. 

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