cpu utilization of the process in "##.#" format.
Currently, it is the CPU time used divided by the time the
process has been running (cputime/realtime ratio),
expressed as a percentage. It will not add up to 100%
unless you are lucky. (alias pCPU).

static int pr_pcpu(char *restrict const outbuf, const proc_t *restrict const pp){
unsigned long long total_time; /* jiffies used by this process */
unsigned pcpu = 0; /* scaled %cpu, 999 means 99.9% */
unsigned long long seconds; /* seconds of process life */
total_time = pp->utime + pp->stime;
if(include_dead_children) total_time += (pp->cutime + pp->cstime);
seconds = seconds_since_boot - pp->start_time / Hertz;
if(seconds) pcpu = (total_time * 1000ULL / Hertz) / seconds;
if (pcpu > 999U)
return snprintf(outbuf, COLWID, "%u", pcpu/10U);
return snprintf(outbuf, COLWID, "%u.%u", pcpu/10U, pCPU%10U);
}