diff --git a/mlair/plotting/postprocessing_plotting.py b/mlair/plotting/postprocessing_plotting.py
index da477718b77ee2e2b8cb20580b77f2ec8c1c3b7c..c6ec6655e679abbb458507df1080804acc369900 100644
--- a/mlair/plotting/postprocessing_plotting.py
+++ b/mlair/plotting/postprocessing_plotting.py
@@ -155,10 +155,10 @@ class PlotOversamplingContingency(AbstractPlotClass):
             for threshold in range(self._min_threshold, self._max_threshold):
                 for pred in predictions:
                     ta, fa, fb, tb = self._single_contingency(obs, pred, threshold)
-                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="ta", type=pred.type.values)] = ta
-                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="fa", type=pred.type.values)] = fa
-                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="fb", type=pred.type.values)] = fb
-                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="tb", type=pred.type.values)] = tb
+                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="ta", type=pred.type.values)] = ta + 1
+                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="fa", type=pred.type.values)] = fa + 1
+                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="fb", type=pred.type.values)] = fb + 1
+                    contingency_array.loc[dict(thresholds=threshold, contingency_cell="tb", type=pred.type.values)] = tb + 1
             logging.info(f"{station}: finished")
         return contingency_array