2022 - 46.8 percent
2020 - 66.8 percent
2018 - 50.3 percent
2016 - 60.2 percent
2014 - 36.7 percent
The major difference in 2022 is that Americans had two years of catastrophic governance and still chose to not vote and/or voted for the democrats, the cause of the catastrophe. Either choice is beyond human comprehension.
I went looking too and got this:
“Reported voting fell from 64% in 2008 to 46% in 2010. From 2012 to 2014, it dropped from 62% to 42%.”
So that would be a 18 pt. difference between 2008 and 2010, and a 20 pt. difference between 2012 and 2014.
(But this is “reported voting.” May differ slightly from actual certified election statistics.)
Another thing I got was that of the 10 midterm elections since 2002, 2022 turnout was the second highest turnout of midterm elections with 2018 being the highest. (That report just lists the data as “turnout rates,” so I’m assuming that it’s not people just reporting whether or not they voted, but actual turnout of eligible voters.)