From USA Today:

ACT test: The number of perfect scores is soaring everywhere, as expensive test prep booms

Hannah Sparling and Dan Horn, Cincinnati Enquirer May 1, 2019 | CINCINNATI – Last week, Walnut Hills High School announced that 17 of its students scored a perfect 36 on the ACT college admissions test. Things got a little crazy after that. Jimmy Fallon joked about the Cincinnati school on the “Tonight Show.” Social media blew up with congratulations and conspiracy theories. And test experts buzzed about what it all meant. But was it really that unusual? Yes. But maybe not as unusual as everyone first thought. Turns out, the number of perfect ACT scores nationwide has more than doubled since 2015 and is six times higher today than it was eight years ago. In 2010, 1 of every 2,600 students nailed a perfect score. In 2018, it was 1 of every 500. … The average test scores haven’t changed much. Those have hovered around 21 for at least the past five years.

Number of ACT test takers have gone up 25% from 2011 to 2017. Various states now pay for all high school juniors in the state to take the ACT or the SAT.

The scores at the top, however, have changed dramatically, widening the gap between the privileged and the rest. At Walnut Hills, an elite, public college-preparatory school, nine students posted perfect scores in 2018 and seven more have done it so far this year. A total of 17 juniors and seniors at the school currently boast perfect scores, with one of those earned in 2017. … If the test is essentially the same, why are so many more students acing it?

How do we know the ACT is the same?

The most likely answer is a booming test-preparation industry that’s built on the hopes and fears of students and parents who are willing to work – and pay – to get an edge.

The test prep industry back when future Senator Chuck “4 800s” Schumer was running the mimeograph machine for Stanley Kaplan was initially focused on the coastal-oriented SAT rather than the heartlandish ACT. But that’s faded over the years. For example, the two Cincinnati area high schools that are the focus of this article have lots of Asian Tiger Children.