SNAFU vs helter-skelter

SNAFU

noun
  • A ridiculously chaotic situation. 

  • A major glitch or breakdown. 

helter-skelter

noun
  • A helical fairground slide. 

  • Confusion or turmoil. 

adv
  • In confused, disorderly haste. 

adj
  • Carelessly hurried and confused. 

How often have the words SNAFU and helter-skelter occurred in a corpus of books? (source: Google Ngram Viewer )