reading extended data from a sensor
You should read the complete datasheet. Absolute accuracy data is only given for the operating pressure range of 300 to 1200 mbar. Relative accuracy data is given only for 700 to 1000 mbar. There is no accuracy data for the range of 10 to 300 mbar and 1200 to 2000 mbar.
But the air pressure on top of the Mount Everest is 325 mbar and down at the Dead Sea about 1065 mbar. The operating pressure range should be sufficient for an altimeter not used in passenger airplanes.