XINU OS - How can I count number of interrupts handlers that occured?

Question

In DOSBOX XINU operating system; I want to count number of interrupts handlers that occurred in x time. Is there a global variable to be referenced to?

I think in the header IO.H,

extern  int nmaps;      /* number of active intmap entries  */

since the struct intmaps saves data about every INT in vector table

is responsible for it?