diff --git a/octoprint_printhistory/eventHandler.py b/octoprint_printhistory/eventHandler.py
index e9d4b78..95ca623 100644
--- a/octoprint_printhistory/eventHandler.py
+++ b/octoprint_printhistory/eventHandler.py
@@ -52,15 +52,15 @@ def eventHandler(self, event, payload):
                         filamentVolume = fileData["analysis"]["filament"]["tool0"]["volume"]
                         filamentLength = fileData["analysis"]["filament"]["tool0"]['length']
 
-                        currentFile["filamentVolume"] = filamentVolume
-                        currentFile["filamentLength"] = filamentLength
+                        currentFile["filamentVolume"] = filamentVolume if filamentVolume is not None else 0
+                        currentFile["filamentLength"] = filamentLength if filamentLength is not None else 0
 
                     if "tool1" in fileData["analysis"]["filament"]:
                         filamentVolume = fileData["analysis"]["filament"]["tool1"]["volume"]
                         filamentLength = fileData["analysis"]["filament"]["tool1"]['length']
 
-                        currentFile["filamentVolume2"] = filamentVolume
-                        currentFile["filamentLength2"] = filamentLength
+                        currentFile["filamentVolume2"] = filamentVolume if filamentVolume is not None else 0
+                        currentFile["filamentLength2"] = filamentLength if filamentLength is not None else 0
 
                     estimatedPrintTime = fileData["analysis"]["estimatedPrintTime"] if "estimatedPrintTime" in fileData["analysis"] else 0
 
diff --git a/octoprint_printhistory/static/css/printhistory.css b/octoprint_printhistory/static/css/printhistory.css
index 20d8789..7d42fc1 100644
--- a/octoprint_printhistory/static/css/printhistory.css
+++ b/octoprint_printhistory/static/css/printhistory.css
@@ -25,3 +25,15 @@
     font-size: 85%;
     color: #999;
 }
+
+#tab_plugin_printhistory .summary {
+    margin-bottom: 5px;
+}
+
+#tab_plugin_printhistory .summary th {
+    font-weight: bold;
+    border-top: 1px solid #ddd;
+    background-color: #f9f9f9;
+    padding-top: 10px;
+    padding-bottom: 10px;
+}
diff --git a/octoprint_printhistory/templates/printhistory_tab.jinja2 b/octoprint_printhistory/templates/printhistory_tab.jinja2
index c7731bd..c08bfcf 100644
--- a/octoprint_printhistory/templates/printhistory_tab.jinja2
+++ b/octoprint_printhistory/templates/printhistory_tab.jinja2
@@ -69,7 +69,7 @@ Refresh <a href="#" data-bind="click: function() { requestData({force: true}); }
     </ul>
 </div>
 
-<table class="table table-striped table-hover table-condensed table-hover">
+<table class="table table-striped table-hover table-condensed table-hover summary">
     <thead>
         <tr>
             <th style="width: 63%">Total:</th>
@@ -79,7 +79,7 @@ Refresh <a href="#" data-bind="click: function() { requestData({force: true}); }
     </thead>
 </table>
 
-<table class="table table-striped table-hover table-condensed table-hover">
+<table class="table table-striped table-hover table-condensed table-hover summary">
     <thead>
         <tr>
             <th style="width: 63%">Average:</th>