Astro-databank is the resource for researchers in astrology. It is a repository of birth information of many thousands of people and events and includes biographic data as well as the birth time, place, and date. Of high utility is the included Rodden Rating which tells us the accuracy of each chart.
An AA rating is "Data as recorded by the family or state". The expectation of many researchers is that AA data is of the highest accuracy possible and can be used freely. In the following, I show statistically that it is extremely unlikely that the AA rating charts altogether are accurate. I will be considering charts of people only and only those born at or after 1930.
From here on, I will try to state things as explicitly as possible.
The common assumption (the null hypothesis) is that AA rating charts are all of high accuracy and hence, taken altogether, exhibit behavior of high accuracy. My assertion (the alternate hypothesis) is that AA rating charts do not exhibit behavior of accurate birth data.
One behavior of accurate birth data is that the minute of birth is evenly distributed. That is to say, a birth time of 8 minutes after the hour is not expected to happen much more or less than a birth time of 9 minutes after the hour, for example.
The following is a simulation of a uniform distribution so that you you know what its plot looks like.