formula of getting maximum deviation %FS

Dear sir, Could you help me, how they get the Maximum deviation %FS - As found +/- 0.75 and as left +/- 0.13 for the rosemount 2088 0 to 101.5 PSIG INPUT 4 to 20 mA output. could you pls. send me the formula.

Range input pressure: 0.00, 18.13, 50.75, 76.13, 101.50

Rising O/P mA Actual: 4.0, 8.0, 12.0, 16.0, 20.0

Rising measured as found: 4.09, 8.052, 12.075, 16.091, 20.120

Rising measured as left: 4.00 , 7.996 11.998 ,16.013 , 20.021

Rising Error mA as found: 0.059 , 0.052 , 0.075 , 0.091 0.120

Rising Error mA as left: 0.000 , -0.004 , -0.002 , 0.013 , 0.021

thanks, raffy