Question: What are the factors that can cause the measured VCCL_GXBL current out of the range of the estimated value ?

I am using Power analzyer Tool to estimate the current consumption(vectorless) of each voltage supply for Cyclone V . For VCC_GXBL voltage supply , the estimated current is 4mA but the actual current measurement was 6 mA. For power analyzer tool , the accuracy is about +/- 20%. I used picoammeter to measure the current. The accuracy of the picoammeter for 20mA range is +/- 0.1%. Measured VCCL_GXBL current a few times on different boards, the measured current is about 6mA.