
Taking an iq test is like taking the SATs, like if you prep for it you can score 15 points higher on average. A large part of your score is also affected by the people who write your questions and how similar the language they use is to the language used in your region resulting in a better understanding of the question. So there's enough wiggle room in the results I'd say to assume someone who gets a 97 could easily retake the test and get 103 making it about average.