Yes a lot will depend where you live and also the test publisher. My post was an oversimplified explanation.
Essex standardise without modification for age.
Age standardisation is not always done in months, it could be some other grouping.
I think I read that Kent standardise against the national average not the cohort.
In Bucks they have 110 standardised score as the average, as opposed to 100.
CEM exams in Birmingham and Warks have a much wider spread of standardised scores.
In some areas like Glos. The score is calculated for individual school cohorts as opposed to a single fixed standardised score applied across the test schools.
Indies don't tend use age standardisation.
I'm sure the list goes on and on.
DS has just turned 9 (so one of the youngest going into Y5) and he is scoring somewhere between 70 - 85% on the 9 - 10 Bonds (done about 10 of each so far and depends on how quickly he wants to be finished!) - am hoping he's on the right track??
If you have a look in the regional areas of the forum you will get more specific information about the test types, suggested papers and scores.