diff --git a/pretix_advanced_stats/templates/pretix_advanced_stats/advanced_stats.html b/pretix_advanced_stats/templates/pretix_advanced_stats/advanced_stats.html
index 25fb881..e617866 100644
--- a/pretix_advanced_stats/templates/pretix_advanced_stats/advanced_stats.html
+++ b/pretix_advanced_stats/templates/pretix_advanced_stats/advanced_stats.html
@@ -51,35 +51,41 @@ <h3 class="panel-title">{% trans "Aggregate sellout" %}</h3>
     <div class="panel-body">
         <div class="row">
             <div class="col-md-6">
-                <h4>{{aggregate_previous_event.0.event_name}}</h4>
+                <h4>{{aggregate_current_event.0.event_name}}</h4>
                 <table class="table">
                     <thead>
                         <th>{% trans "Period" %}</th>
                         <th>{% trans "# tickets" %}</th>
+                        {% if aggregate_previous_event.0.event_name %}
+                            <th>Diff with {{aggregate_previous_event.0.event_name}}</th  >
+                        {% endif %}
                     </thead>
                     <tbody>
-                        {% with start_month=aggregate_previous_event.0.month_name|slice:":3" %}
-                        {% for r in aggregate_previous_event|slice:"1:" %}
+                        {% with start_month=aggregate_current_event.0.month_name|slice:":3" %}
+                        {% for r in aggregate_current_event|slice:"1:" %}
                         <tr>
                             <td>{{ start_month }}-{{ r.month_name|slice:":3" }}</td>
                             <td>{{r.cumulative_count}}</td>
+                            {% if aggregate_previous_event.0.event_name %}
+                            <td>{{r.diff}}</td>
+                            {% endif %}
                         </tr>
                         {% endfor %}
                         {% endwith %}
-                        
                     </tbody>
                 </table>
             </div>
+            {% if aggregate_previous_event.0.event_name %}
             <div class="col-md-6">
-                <h4>{{aggregate_current_event.0.event_name}}</h4>
+                <h4>{{aggregate_previous_event.0.event_name}}</h4>
                 <table class="table">
                     <thead>
                         <th>{% trans "Period" %}</th>
                         <th>{% trans "# tickets" %}</th>
                     </thead>
                     <tbody>
-                        {% with start_month=aggregate_current_event.0.month_name|slice:":3" %}
-                        {% for r in aggregate_current_event|slice:"1:" %}
+                        {% with start_month=aggregate_previous_event.0.month_name|slice:":3" %}
+                        {% for r in aggregate_previous_event|slice:"1:" %}
                         <tr>
                             <td>{{ start_month }}-{{ r.month_name|slice:":3" }}</td>
                             <td>{{r.cumulative_count}}</td>
@@ -89,11 +95,11 @@ <h4>{{aggregate_current_event.0.event_name}}</h4>
                     </tbody>
                 </table>
             </div>
+            {% endif %}
         </div>
     </div>
 </div>
 
 <script src="{% static "pretix_advanced_stats/stats.js" %}"></script>
-
 {%endif%}
 {% endblock content %}
\ No newline at end of file
diff --git a/pretix_advanced_stats/views.py b/pretix_advanced_stats/views.py
index 75c84e6..8222091 100644
--- a/pretix_advanced_stats/views.py
+++ b/pretix_advanced_stats/views.py
@@ -130,8 +130,19 @@ def get_context_data(self, **kwargs):
             if comparison_event
             else None
         )
-        aggregate_previous_event = self.cumulative_tickets(tickets_previous_event)
+        aggregate_previous_event = (
+            self.cumulative_tickets(tickets_previous_event)
+            if tickets_previous_event
+            else []
+        )
         aggregate_current_event = self.cumulative_tickets(tickets_current_event)
+        if aggregate_previous_event:
+            for r_current, r_previous in zip(
+                aggregate_current_event, aggregate_previous_event
+            ):
+                r_current["diff"] = (
+                    r_current["cumulative_count"] - r_previous["cumulative_count"]
+                )
         ctx.update(
             {
                 "events": [