How to add a numerical order dinamically on jquery

I was told to add a numeric order on a table, but with the condition that when you are adding a table it starts to count from the zero and then you delete the table it throws a dynamical order not 3-5(if i delete 4), I mean it should maintain the order list 1-2-3-4-5 I have a big code and do not want to place it here. Just I have function and

$('td.form_id').each(function(i) {
  $(this).text(i + 1);
});

I want to apply it on my function.

shortly about my function I have a table with the hidden id when I click it it shows me table

<table id="tablo">
  <thead>
    <tr>
      <th></th>
      <th id="tab">Name</th>
      <th id="tab">surname</th>
      <th id="tab">string</th>

      <td>
        <input style="background-color:green; color: white; width: 135px" type="button" class="add" value="Əlavə+">
      </td>

    </tr>
    <tr hidden class="form_id">
      <td>
        <input type="text" style='width:250px'>
      </td>
      <td>
        <input type="text" style='width:250px'>
      </td>
      <td>
        <input type="text" style='width:250px'>
      </td>
      <td>
        <span><a class='fa fa-edit save' style='margin-left:30px' href='javascript: void(0);'>saxla</a></span>
      </td>
    </tr>
  </thead>
  <tbody>
    <tr>

    </tr>
  </tbody>

And a function which is appearing a table each time with the help of append something like this

$(document).ready(function() {

  $(".add").click(function() {

    //$("#td").show();
    var value = "<tr><td class='form_id' style='width:20px' >" + i + "</td><td  style='width:250px'><input type='text'  style='width:250px'></td><td  style='width:250px'><input type='text'  style='width:250px'></td><td  style='width:250px'><input type='text'  style='width:250px'></td><td><span ><a class='fa fa-edit save' style='margin-left:30px' href='javascript: void(0);'>saxla</a></span><span class='delete' style='margin-left:30px'><a class='glyphicon glyphicon-trash'href='javascript: void(0);'>delete</a></span></td>";
    $("table tbody").append(value);

  });
});