I built a circuit according to recommended schematic in the datasheet and measured efficiency vs Iout to satisfy the figure in the datasheet. Conditions; Ca = 8.6pF, Cout = 2x22uF Vin = 5V, Ra=348.5k ohm , Rb= 75k,110, 162k,221k,357k 511k (testing in various Vout). According to outcomes of the measurements, I create following graphic. And all results includes in the attachment. There is almost %20 difference on efficiency between my measurements and datasheet. Do you have any idea about this?