1zmodload zsh/datetime
 2runs=${1:-10}
 3total_ms=0
 4for i in {1..$runs}; do
 5  start=$EPOCHREALTIME
 6  zsh -i -c exit >/dev/null 2>&1
 7  end=$EPOCHREALTIME
 8  delta_ms=$(( (end - start) * 1000 ))
 9  total_ms=$(( total_ms + delta_ms ))
10  printf "run %2d: %3.0f ms\n" "$i" "$delta_ms"
11done
12printf "\nAverage: %.0f ms\n" "$(( total_ms / runs ))"