while reading an excel the you will automatically get in string format, right?
if you select preserve format option then you will be getting the format you have selected on excel.
Could you let us know how are you retrieving/how is the the dt_Statistics datatable prepared ? Is it by using the Build Datatable Activity ? If so, then maybe changing the type from String to Object to all the columns present in the Build Datatable activity would be another possible solution.
Let us know if this is a possibility for your case.