No slight intended - standardising test scores is a complex and expensive operation, it requires (a) very sound statistical knowledge, (b) a large reference group to standardise against and (c) a large enough test cohort to make it worthwhile. Given that only about 1000 take the two tests (~600 KES/~400 KEHS), a standardisation exercise would actually be a bigger operation than running the test itself.
If any allowance is being made for age it would therefore likely be somewhat subjective and approximate, as I suspect happens in the indies pist refers to. (For example, you could probably graph scores against age in Excel and plot a trendline. That's "taking age into account" but it isn't "standardisation".)