Here's one that should do the trick without splitting thousands of lines. I'm not sure if it's really faster, but in the spirit of TIMTOWTDI:

open LOG, "test_log";

my %results;

while (<LOG>) 
{
  /\.(\w+) (\d\d\d)$/ and $results{$1}{$2}++;
}

close LOG;

foreach my $type (sort keys %results)
{
  foreach my $code (sort keys %{$results{$type}})
  {
    print "$type $code ".$results{$type}{$code}."\n";
  }
}
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The chicken tracks at the beginning are a regular expression that looks for the letters after the last . and the three-digit code at the end. It assumes that the comments at the beginning of the file won't have a three-digit code at the end.