How to merge the contents of Multiple files stored in the Hash and generate the merged file output along with Header in tabular form

For example, i have 2 files (File1.txt and File2.txt) and generate the present the output with Header Information as below

I was able to present the merged file but without header information :(

Header information i am missing to put is "Distance Fuel_Consumption_Curr Fuel_Consumption_Baseline1" in the output generated as files will get processed

Monks Please help...

Your help in understanding the logic will be greatly appreciated 

1. Current_results (File1.txt):
Distance   Fuel_Consumption
60        2.0
80        2.2
100        3.0
200        5.5
<EOF>

2. Baseline1 (File2.txt):
Distance   Fuel_Consumption
60        1.0
80        1.5
100        2.3
200        4.2
<EOF>

3. Output (Report.txt)

Distance  Fuel_Consumption_Curr    Fuel_Consumption_Baseline1
60       2.0            1.0
80       2.2            1.5
100       3.0            2.3
200       5.5            4.2
<EOF>

[download]

Code written to process the files 

#!/usr/bin/perl -w

use strict;
use Data::Dumper qw(Dumper); 


my @list_of_files =  qw(file1.txt file2.txt);
my %data;
my $file_num = 0;
my $Distance;


foreach my $file_name (@list_of_files) {
    $file_num++;
    my $file = 'File'.$file_num;
    my $flag = 0;

    open FH, $file_name or die "Cannot open $file_name. $!";
    while(<FH>){
        chomp;
        if($_ =~ /\s*(\d+)\s*(\d+\.\d+)/){
            $Distance=$1;
             $data{$Distance}{$file}{'Fuel_Consumption'}=$2;
            next;
        }
       }
    close FH;
}

  print Dumper(\%data); 

  my ($tmpDist,$tmpFile,$tempValue);
  print "Merged output\n";
  
 foreach $tmpDist (sort{ $a <=> $b } keys( %data ) ) 
 {
    print "$tmpDist";
    foreach $tmpFile (sort{ lc($a) cmp lc($b) } keys( %{$data{$tmpDist
+}} ) )
     {
      $tempValue=$data{$tmpDist}{$tmpFile}{'Fuel_Consumption'};
       print "\t $tempValue";
     }
    print "\n";
 }

[download]

Output generated is as follows but without header information is as follows

Header missing is : Distance Fuel_Consumption_Curr Fuel_Consumption_Baseline1 

60       2.0     1.0
80       2.2     1.5
100      3.0     2.3
200      5.5     4.2

[download]

In reply to How to merge the contents of Multiple files stored in the Hash and generate the merged file output along with Header in tabular form by Anonymous Monk

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