for (0..15) {
    $a{'a'}{$_} = 0;
    print scalar %{$a{'a'}}, "\n";
}

##</code><code>##

1/8
2/8
3/8
3/8
3/8
4/8
5/8
6/8
8/16
9/16
10/16
11/16
11/16
11/16
12/16
15/32

##</code><code>##

print scalar @{[%{$a{'a'}}]}, "\n";