diff --git a/src/measurements/MeasurementContainer.js b/src/measurements/MeasurementContainer.js
index f48110a..317fcee 100644
--- a/src/measurements/MeasurementContainer.js
+++ b/src/measurements/MeasurementContainer.js
@@ -339,10 +339,10 @@ class MeasurementContainer {
     }
 
     if (asNumber) {
-      return Object.keys(this.measurements[this._currentType][this._currentVariant]).map(this._convertPositionNum2Str);
+      return Object.keys(this.measurements[this._currentType][this._currentVariant]);
     }
-    
-    return Object.keys(this.measurements[this._currentType][this._currentVariant]);
+
+    return Object.keys(this.measurements[this._currentType][this._currentVariant]).map(this._convertPositionNum2Str);
   }
 
   clear() {