#!/usr/bin/perl -w

use strict;
use Data::Dumper;

sub Statistics {

   my %param;

   if (ref $_[0] eq 'HASH') {
      %param = %{$_[0]};
   }
   elsif (@_ & 1) {
      die 'Not enough arguments';
   }
   else {
      %param = @_;
   }

   print Dumper(%param);
}

Statistics( 'Key1','Value1','Key2','Value2' );

my $hashref = {
   'Key1' => 'Value1',
   'Key2' => 'Value2',
};

Statistics( $hashref );