I want to make a hash of arrays. I thought I was doing it correctly, but apparently I'm not. I expect a result like this:

10
a l
11
b m
[download]

Here's the code:

#!/usr/bin/perl

use strict;
use warnings;

my $filename = $ARGV[0];
my $outFilename = $ARGV[1];
open OUTFILE, ">", $outFilename or die $!;


open FILE, $filename or die $!;

my $id;
my $date;

while(<FILE>)
{
    my $line = $_;
    if($_ =~ /(.*?)\t+(.*?)\[/ ) {
        $id = $1;
        $date = $2;
        print OUTFILE "$id\t$date\n";
    }

my $key;
my $i;
my %HoA;

push @{ $HoA{$id} }, $date;
    

my $k;
foreach $k (keys %HoA) {
    print "$k\n\t";
   foreach (@{$HoA{$k}}) {
      print " $_";
   }
   print "\n";
}
}
[download]

The input is like this:

10        a[
11        b[
12        c[
13        d[
14        e[
15        f[
16        g[
17        h[
18        i[
19        j[
20        k[
10        l[
11        m[
12        n[
13        o[
14        p[
15        q[
16        r[
17        s[
18        t[
19        y[
20        v[
[download]

But the output is sadly like this:

10
     a
11
     b
12
     c
13
     d
14
     e
15
     f
16
     g
17
     h
18
     i
19
     j
20
     k
10
     l
11
     m
12
     n
13
     o
14
     p
15
     q
16
     r
17
     s
18
     t
19
     y
20
     v
[download]

This confuses me because it looks like it is making more than one hash entry per key. What am I doing wrong here?