C# DataTable to Object Conversion Issue – Asp.net

I’ve written a piece of code for converting a DataTable object(which is created from an uploaded excel) to a list of custom object(ExcelTemplateRow in my case). While this method works fine when the values are supplied as expected(in terms of data type of the corresponding column), the code breaks and throws the below error when I try to give a random value(and hence the data type changes):

Object of type 'System.String' cannot be converted to type 'System.Nullable`1[System.Double]'

Below is the method for converting DataTable object to list:

public static List<T> ConvertToList<T>(DataTable dt)
        {
            var columnNames = dt.Columns.Cast<DataColumn>().Select(c => c.ColumnName.ToLower()).ToList();
            var trimmedColumnNames = new List<string>();

            foreach (var columnName in columnNames)
            {
                trimmedColumnNames.Add(columnName.Trim().ToLower());
            }

            var properties = typeof(T).GetProperties();
            return dt.AsEnumerable().Select(row => {
                var objT = Activator.CreateInstance<T>();

                foreach (var property in properties)
                {
                    if (trimmedColumnNames.Contains(property.Name.Trim().ToLower()))
                    {
                        try
                        {
                            if(row[property.Name] != DBNull.Value)
                            {
                                property.SetValue(objT, row[property.Name]);
                            }
                            else
                            {
                                property.SetValue(objT, null);
                            }
                            
                        }
                        catch (Exception ex) 
                        { 
                            throw ex; 
                        }
                    }
                }
                return objT;
            }).ToList();
        }

My custom object looks somewhat like this:

 public class ExcelTemplateRow
{
  public string? Country {get; set;}
  public double? Year {get; set;}
  //....
  //....
}

In the excel that I’m uploading, for the Year field, the code works fine when I give proper double values viz 2020, 2021, 2022 etc. but the code breaks when I give something wrong e.g 2023g. It then assumes I’m passing a string and hence the error. I tried by changing the declaration of the Year property to public object? Year {get; set;} but it doesn’t help. I want to make the method robust enough to handle such scenarios. Any help and I’d be highly grateful.