🚀 go-pugleaf

Can anyone suggest a source of information on procedure call statistics?
In particular I am interested in the following topic:

	During execution of a program, let d be the procedure call depth
	(i.e., the number of procedure calls minus the number of returns
	that have been executed).  Let C(d) be the number of calls that
	are made during a program's execution by procedures of depth d.
	Let S be the total number of procedure calls of any depth.  
	
Obviously, the function C(d)/S is characteristic of particular software,
but is there any information available about what the function C(d)/S 
typically looks like? 

	What is a reasonable expected value for the function? 

	Better yet, what is a reasonable distribution function for it?

Any specific data or pointers to relevant literature will be
appreciated.