I know you can never find out a person HIV status because of confidentiality rules?

but is there a way to find out how many times a person got tested in a given amount of time? like say so and so got tested for hiv antibodies 3 times in 4 years.ect. obviously they were negative the first two times to get tested a third time down the road(and it doesn't matter if people know your clean) and the results of the third test can either be positive or negative, we don't know since that was the last test taken. I'm sure theres a way to find this information out, how would I go about it?