#!/usr/bin/perl
###########################################
# An welchem Tag im Monat is IBM am 
# teuersten?
# Mike Schilli, 2002 (m@perlmeister.com)
###########################################
use warnings;
use strict;

use QuoteDB 'quotes.db';

my %per_day = ();

for my $d (1 .. 31) {
  for my $y (1995 .. 2001) {
    for my $m (1 .. 12) {
      my ($p) = ($per_day{$d} ||= []);
      $p->[0] += quote("IBM", $y, $m, $d);
      $p->[1]++;
      $p->[2] = $p->[0] / $p->[1];
    }
  }
}

for my $d (sort { $per_day{$b}->[2] <=> 
                  $per_day{$a}->[2] } 
           keys %per_day) {
    printf "%02d: %.2f\n", $d, 
           $per_day{$d}->[2];
}