counting new files per minute over 3k in a directory

count.pl

#!/usr/bin/perl

$p = -1;
$intr = 2;
@minute = ();
while(1) {
 $c = `find ./scraped -size +3k -ls|wc -l`;
 chomp($c);
 if ($p>=0) {
  $t = $c - $p;
  push @minute, $t;
  if (scalar(@minute)>60/$intr) {
   shift @minute;
  }
  $tm=0;
  foreach(@minute) {
   $tm+=$_;
  }
  print "Per $intr s: $t, per minute: $tm, per 15m: ".($tm*15).", per 30m: ".($tm*30).", per hour: ".($tm*60)." total current: $c\n";
 }

 $p = $c; 
 sleep $intr;
}