ADF7242 output power

Hi,

The ADF7242 datasheet mentions that 3dBm output is present in IEEE 802.15.4-2006 mode, when operating under nominal mode.

Why does it indicate in figure 50 of the adf7242 datasheet, that the output maximum is approx. -6dBm, even when the device is in IEEE 802.15.4-2006 with output power = 3dBm.?