datatables sort

HTML

<script src="https://cdn.datatables.net/1.10.9/js/jquery.dataTables.min.js"></script>
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.9/css/jquery.dataTables.min.css">
<table id="example" border="1">
    <thead>
        <tr><th></th><th></th><th></th><th>sort 2015</th><th>sort 2016</th></tr>
         <tr><th>sort 2012</th><th>sort 2013</th><th>sort 2014</th><th></th><th></th></tr>
    </thead>
    <tbody>
        <tr><td>23</td><td>11</td><td>900</td><td>100</td><td>2358</td></tr>
        <tr><td>10</td><td>45</td><td>410</td><td>1</td><td>531</td></tr>
        <tr><td>64</td><td>126</td><td>6310</td><td>85</td><td>7</td></tr>
        <tr><td>86</td><td>524</td><td>520</td><td>65</td><td>68</td></tr>
    </tbody>
</table>

CSS

#example thead th {
   cursor:pointer;
}

JavaScript

$('#example').DataTable({
    "paging": false,
    "orderCellsTop": true,
    "dom": '<"top"i>rt<"clear">',
    "info": false
});

 $('#example').on('click', 'tr:eq(1) th', function(){
    var index = $(this).parent().find('th').index(this);    
    var cellTop = $(this).closest('thead').children().find('tr:eq(1) th:eq('+index +')');
    $(cellTop).trigger('click');
 });