title: awk to count number of occurrences in a Column and print in new column
body: <p>I have a large file in the following format:</p>
  
  <pre><code>NC_019859.2 Gnomon  exon    58334   58504   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    54573   54723   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    52624   52680   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    52413   52551   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    28715   28784   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    26768   26814   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    25856   25914   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    25374   25727   .   -   .   GeneID:110014915
  NC_019859.2 Gnomon  exon    70772   70841   .   -   .   GeneID:110017276
  NC_019859.2 Gnomon  exon    70672   70687   .   -   .   GeneID:110017276
  NC_019859.2 Gnomon  exon    70494   70586   .   -   .   GeneID:110017276
  NC_019859.2 Gnomon  exon    69020   69335   .   -   .   GeneID:110017276
  NC_019859.2 Gnomon  exon    68831   68928   .   -   .   GeneID:110017276
  NC_019859.2 Gnomon  exon    68251   68721   .   -   .   GeneID:110017276
  NC_019859.2 Gnomon  exon    89665   89909   .   +   .   GeneID:110014398
  NC_019859.2 Gnomon  exon    91117   91579   .   +   .   GeneID:110014398
  NC_019859.2 Gnomon  exon    119534  120075  .   -   .   GeneID:101166461
  NC_019859.2 Gnomon  exon    118137  118262  .   -   .   GeneID:101166461
  NC_019859.2 Gnomon  exon    117700  117831  .   -   .   GeneID:101166461
  NC_019859.2 Gnomon  exon    117326  117490  .   -   .   GeneID:101166461
  </code></pre>
  
  <p>I want following desired out put </p>
  
  <pre><code>NC_019859.2 Gnomon  exon    58334   58504   .   -   .   GeneID:110014915    exon_number:1 
  NC_019859.2 Gnomon  exon    54573   54723   .   -   .   GeneID:110014915    exon_number:2
  NC_019859.2 Gnomon  exon    52624   52680   .   -   .   GeneID:110014915    exon_number:3
  NC_019859.2 Gnomon  exon    52413   52551   .   -   .   GeneID:110014915    exon_number:4
  NC_019859.2 Gnomon  exon    28715   28784   .   -   .   GeneID:110014915    exon_number:5
  NC_019859.2 Gnomon  exon    26768   26814   .   -   .   GeneID:110014915    exon_number:6
  NC_019859.2 Gnomon  exon    25856   25914   .   -   .   GeneID:110014915    exon_number:7
  NC_019859.2 Gnomon  exon    25374   25727   .   -   .   GeneID:110014915    exon_number:8
  NC_019859.2 Gnomon  exon    70772   70841   .   -   .   GeneID:110017276    exon_number:1
  NC_019859.2 Gnomon  exon    70672   70687   .   -   .   GeneID:110017276    exon_number:2
  NC_019859.2 Gnomon  exon    70494   70586   .   -   .   GeneID:110017276    exon_number:3
  NC_019859.2 Gnomon  exon    69020   69335   .   -   .   GeneID:110017276    exon_number:4
  NC_019859.2 Gnomon  exon    68831   68928   .   -   .   GeneID:110017276    exon_number:5
  NC_019859.2 Gnomon  exon    68251   68721   .   -   .   GeneID:110017276    exon_number:6
  NC_019859.2 Gnomon  exon    89665   89909   .   +   .   GeneID:110014398    exon_number:1
  NC_019859.2 Gnomon  exon    91117   91579   .   +   .   GeneID:110014398    exon_number:2
  NC_019859.2 Gnomon  exon    119534  120075  .   -   .   GeneID:101166461    exon_number:1
  NC_019859.2 Gnomon  exon    118137  118262  .   -   .   GeneID:101166461    exon_number:2
  NC_019859.2 Gnomon  exon    117700  117831  .   -   .   GeneID:101166461    exon_number:3
  NC_019859.2 Gnomon  exon    117326  117490  .   -   .   GeneID:101166461    exon_number:4
  </code></pre>
  
  <p>I tried this command and got.</p>
  
  <pre><code>awk '{a[$9]++}END{for(i in a){print i, a[i]}}' 
  GeneID:110014915 8
  GeneID:110017276 6
  GeneID:110014398 2
  GeneID:101166461 4
  </code></pre>
  
  <p>Thanks in advance, looking forward for a positive response.</p>