formattedTotal);
            return data;

          }
         },
        "order": [[1, "desc"]],
        "columns": [
          {"data": first_column,
           "render": first_column_render
          },
          {"data": "possible_savings", render: $.fn.dataTable.render.number(',', '.', 0, '£' ), className: "text-right"},
          {"data": "price_per_unit", render: $.fn.dataTable.render.number(',', '.', 2, '£' ), className: "text-right"},
          {"data": "lowest_decile", render: $.fn.dataTable.re