I'm not a lawfag, but was perusing Roberts' end of the year report for the SCOTUS, and I wonder if any of the stats he mentions (at the end, in the appendix, which is odd to me…why put it all at the end??) could be useful for those critical of the 70K sealed proceedings number to give support to what's "normal". I realize it's apples and oranges in a way, but not sure if there's a correlation we can use. A lawfag's eyes would be helpful.
https://www.supremecourt.gov/publicinfo/year-end/2018year-endreport.pdf
Reports back to 2000
https://www.supremecourt.gov/publicinfo/year-end/year-endreports.aspx