The rate of reports to child protective services

I found these to be astoundingly high, so much so that I am wondering if there is an error in the data. From the National Library of Medicine:

37.4% of all children experience a child protective services investigation by age 18 years. Consistent with previous literature, we found a higher rate for African American children (53.0%) and the lowest rate for Asians/Pacific Islanders (10.2%).

I have no expertise in this area, but the point of the paper is trying to differentiate between first time investigations and follow up investigations, since presumably children that are investigated once are more likely to be investigated again.

In 2014, 4.57% of all US children had a maltreatment investigation... Of these, about half (2.39%) had no previous investigation in the 2003–2014 database. After adjusting for database-first-time investigation rates as described in the preceding section, we estimate that 2.09% had a true first-time investigation.

It occurs to me that even though I'm a parent, I'm not sure what exactly would cause a CPS investigation and what wouldn't.

If this data is correct, I'm torn between being sad for a whole lot of families and wondering if we're over investigating.