diff --git a/views/bootstrap/class.Charts.php b/views/bootstrap/class.Charts.php
index 70d14f94c..06eed4d2d 100644
--- a/views/bootstrap/class.Charts.php
+++ b/views/bootstrap/class.Charts.php
@@ -349,7 +349,7 @@ $(document).ready( function() {
 			$oldtotal = 0;
 			foreach($data as $item) {
 				echo "<tr>";
-				echo "<td data-sort=\"".$item['key']."\">".htmlspecialchars($item['key'])."</td>";
+				echo "<td data-sort=\"".str_replace('-', '', $item['key'])."\">".htmlspecialchars($item['key'])."</td>";
 				echo "<td>".$item['total']."</td>";
 				if(in_array($type, array('docspermonth')))
 					echo "<td>".sprintf('%+d', $item['total']-$oldtotal)."</td>";