Right after the big teacher reform in California, I signed up for and took (at a cost of $35) the CBEST exam which was to be required of all new teachers beyond that point in time.
I scored in the top 10% without any preparation at all.
70% of the students or graduates taking that first round failed one or more of the four parts.
In my opinion, the test was at an 8th grade level but did have an essay portion that could be considered subjective.
I had no interest in getting a certificate, I was simply making a point for yet another letter to the editor of my local paper where I was busily exposing the shortcomings of our small city (Simi Valley) schools with special emphasis on the local superintendent.
My daughter took the written test when applying for SFPD recently. She says it was a 10 grade reading/literacy level at best, and finished it in about one half the allotted time.
All of these examples are, of course, anecdotal. But illustrative nonetheless.
But, I have seen some books that I read in grade school being printed again and marketed as young adult reading. Duh.