DAC5578: The Offset error and the Gain error

Part Number:DAC5578

Sir,

The offset error and the gain are all measure by (12-bit: 30 and 4050; 10-bit: 12 and 1012; 8-bit: 4 and 250)

For 8-bit version, what is the  Offset error and the Gain error for 0-3 and 251-255?

Thank you

C.T.