minor changes to schema
diff --git a/tools/run_tests/performance/export_utils.py b/tools/run_tests/performance/export_utils.py
index bdb36a5..6df64cc 100644
--- a/tools/run_tests/performance/export_utils.py
+++ b/tools/run_tests/performance/export_utils.py
@@ -86,3 +86,4 @@
   scenario_result['latencies'] = json.dumps(scenario_result['latencies'])
   for stats in scenario_result['clientStats']:
     stats['latencies'] = json.dumps(stats['latencies'])
+  scenario_result['serverCores'] = json.dumps(scenario_result['serverCores'])