Update for the tunnel graph to have the stats my month and type of flights

Back/skydiveLogs-api/DataContract/StatisticForChartResp.cs

@@ -0,0 +1,11 @@
+namespace skydiveLogs_api.DataContract
+{
+    public class StatisticForChartResp
+    {
+        public string Label { get; set; }
+
+        public string Label2 { get; set; }
+
+        public int Nb { get; set; }
+    }
+}