HDC1008 the accuracy of humidity is higher 6~8%

  I am using HDC1008 （200pcs）assembly our products，Temperature  accuracy is good， but  the accuracy of humidity is higher 6~8%， why？  

Is it necessary to open the heating function for reduce humidity ? In that way temperature is error .

   so I'm going to subtract 7% of HDC1008 readings, But in this wayour products 's max  humidity is only 93%.

   Is there  any method to read HDC1008 data over 100% ?