allot vs split up

allot

verb
  • To assign or designate as a task or for a purpose. 

  • To distribute or apportion by (or as if by) lot. 

split up

verb
  • separate, disassociate, cause to come apart. 

  • Cease to be together, break apart from the group. 

adj
  • Divided or separated. 

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