use warnings;
use strict;
use List::Util qw(sum);

my @list = ();
while (<DATA>) {
    push @list, (split)[1];
}
my $avg = (sum @list) / (scalar @list);
print "Average: $avg\n";
1;

__DATA__
One 1 #First
RedBaloons 99 #Second
Normans 1066 #Third
Thunderkiss 1965 #Fourth
Warhammer 40000 #Fifth
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I'm sure there's a CPAN module that'll do it even better, though. ;)