Salesforce Report not Giving correct record count

So we have 1 picklist field - County name( which has 23 option in that picklist)

In report we have to count no of record in each picklist value within 12 months( I have created formula to achieve 12 month scenario like this Month(Today()) - Month(Datevalue(Created Date)).

When I am applying a filter with group by on county name, record count on report is not correct.

Please refer the above attach file 

In first Albany option you can see in report 2 record coming but in list view I have applied filter with county name as Albany 5 record is coming.

Please any help would be appreciated. 

#Reports & Dashboards