Group Subtotal datatable at the bottom

Question

I have a datatable with subtotal. jsfiddle, but this subtotal is at the top and needs to appear at the bottom as subtotal.

Doing tests I found out that it generates the TR when it goes through this line of code

if (last !== group) {
    groupid++;
    $(rows).eq(i).before(
        '<tr class="group"><td>' + group + '</td></tr>'
    );
    last = group;
}

How I would make this TR generate at the end and not at the beginning of each item?