--- /Applications/MAMP/htdocs/moodle/mod/quiz/report/overview/report.php	2022-09-19 11:42:48.000000000 +0100
+++ /Applications/MAMP/htdocs/moodle/mod/quiz/report/overview/report-MDL-60632.php	2022-11-30 12:40:58.000000000 +0000
@@ -752,6 +752,14 @@
         $yaxis->set_label(get_string('participants'));
         $yaxis->set_stepsize(max(1, round(max($data) / 10)));
 
+        // MDL-60632
+        foreach ($data as $databand => $datanum) {
+            if ($databand < 0) {
+                $data["0"] += $datanum; //Add to band 0 
+                unset($data[$databand]); //Remove entry below 0
+            }
+        }
+
         $series = new \core\chart_series(get_string('participants'), $data);
         $chart->add_series($series);
         return $chart;