Doesn't mean anything, can you provide the schematics and the software you used to do this test?
There are multiple possible sources which can cause this.
What board did you use?
What type of filter cap's did you use?
How did you connect the sources to the part/board....?
Can you provide the theoretical calculations showing with all possible factors the worst case scenario?
Others in the community would appreciate to know the details how this data is generated - so can you give some more detail?
I used external reference resistor 1 kOm 5 ppm/°C at REF0-REF1
How did you configure the ADC - in ratiometric mode?
Thanks. I don't have any questions. I just shared information.