             
             checkIsLegal(newValue.dataSets);
             
-            calcMinMax();
+            calcMinMax(start: _lastStart, end: _lastEnd);
             calcYValueSum();
             calcYValueCount();
             

            
            checkIsLegal(newValue.dataSets);
            
            calcMinMax();
            calcYValueSum();
            calcYValueCount();
            

            
            checkIsLegal(newValue.dataSets);
            
            calcMinMax(start: _lastStart, end: _lastEnd);
            calcYValueSum();
            calcYValueCount();
            
