fall behind vs get past

fall behind

verb
  • Used other than figuratively or idiomatically: see fall, behind. 

  • To be late (for a regular event) 

  • To be progressively below average in performance. 

  • to fail to keep up (with) 

get past

verb
  • To cause someone to overcome a source of grief or get through a difficult time. 

  • To cause something to get around a blockage; to cause to get around or surpass something that is in the way. 

  • To get through a difficult time; to overcome a source of grief. 

  • To continue around a blockage; to get around (something); to surpass something that is in the way. 

How often have the words fall behind and get past occurred in a corpus of books? (source: Google Ngram Viewer )