diff --git a/curation/parsers/demographic.py b/curation/parsers/demographic.py
index 2fe2c222..cee6a551 100644
--- a/curation/parsers/demographic.py
+++ b/curation/parsers/demographic.py
@@ -4,14 +4,21 @@
 
 class DemographicData(GenericData):
 
-    def __init__(self,type,value,spreadsheet_name):
+    def __init__(self,type:str,value:str|int|float,spreadsheet_name:str) -> None:
         GenericData.__init__(self,spreadsheet_name)
         self.type = type.strip()
         self.value = value
 
 
+    def update_demographic_data(self) -> None:
+        """ Change the default estimate_type value if no estimate is provided """
+        demographic_keys = self.data.keys()
+        if not 'estimate' in demographic_keys and 'range' in demographic_keys:
+            self.data['estimate_type'] = 'range'
+
+
     @transaction.atomic
-    def create_demographic_model(self):
+    def create_demographic_model(self) -> Demographic:
         '''
         Create an instance of the Demographic model.
         Return type: Demographic model
diff --git a/curation/parsers/sample.py b/curation/parsers/sample.py
index 4b72dfa8..5a8148dc 100644
--- a/curation/parsers/sample.py
+++ b/curation/parsers/sample.py
@@ -72,6 +72,7 @@ def str2demographic(self, field, val):
                         else:
                             variability = value
                         current_demographic.add_data('variability', variability)
+            current_demographic.update_demographic_data()
         return current_demographic