Index: lams_central/web/qb/stats.jsp
===================================================================
diff -u -r7e395b459598e00fe3f644d345bf99d2cd39d70f -r0580a000d442501fbababd51663f7c03cedfbf20
--- lams_central/web/qb/stats.jsp	(.../stats.jsp)	(revision 7e395b459598e00fe3f644d345bf99d2cd39d70f)
+++ lams_central/web/qb/stats.jsp	(.../stats.jsp)	(revision 0580a000d442501fbababd51663f7c03cedfbf20)
@@ -167,17 +167,24 @@
 							<td>
 								<c:out value="${lesson.organisation.name}" />
 							</td>
-							<td>
+							<td title="${lesson.lessonId}">
 								<c:out value="${lesson.lessonName}" />
 							</td>
-							<td>
+							<td title="${activityDTO.activity.activityId}">
 								<c:out value="${activityDTO.activity.title}" />
 							</td>
 							<td>
 								<c:out value="${activityDTO.activity.tool.toolDisplayName}" />
 							</td>
 							<td>
-								<c:out value="${activityDTO.average}" />%
+								<c:choose>
+									<c:when test="${empty activityDTO.average}">
+										-
+									</c:when>
+									<c:otherwise>
+										<c:out value="${activityDTO.average}" />%
+									</c:otherwise>
+								</c:choose>
 							</td>
 						</tr>
 					</c:forEach>
Index: lams_common/src/java/org/lamsfoundation/lams/qb/service/QbService.java
===================================================================
diff -u -r7e395b459598e00fe3f644d345bf99d2cd39d70f -r0580a000d442501fbababd51663f7c03cedfbf20
--- lams_common/src/java/org/lamsfoundation/lams/qb/service/QbService.java	(.../QbService.java)	(revision 7e395b459598e00fe3f644d345bf99d2cd39d70f)
+++ lams_common/src/java/org/lamsfoundation/lams/qb/service/QbService.java	(.../QbService.java)	(revision 0580a000d442501fbababd51663f7c03cedfbf20)
@@ -57,7 +57,7 @@
 		    correctCount = answerCount;
 		}
 	    }
-	    activityDTO.setAverage(Long.valueOf(Math.round(correctCount / total * 100)).intValue());
+	    activityDTO.setAverage(total == 0 ? null : Long.valueOf(Math.round(correctCount / total * 100)).intValue());
 	    activityDTOs.add(activityDTO);
 	}
 	stats.setActivities(activityDTOs);