AD22151 Minimum Magnetic Field Strength

What is the minimum magnetic field strength in Gauss that the AD22151 can reliably measure considering noise sources and what gain would be appropriate?   The application would be a static magnetic field so a bandwidth below 50hz would be appropriate.   The  noise section of the data sheet indicates 1 mV rms noise with 5mV/G would give a a minimum detectable signal of 0.2 Gauss.  Can the AD22151 be used at this level of signal or lower and what would be the external circuit design considerations?   An update to the data sheet giving minimum detectable Gauss levels would be appropriate.