Those are people who actually voted in the off-year election, not people whos view or registration. https://www.statista.com/statistics/319068/party-identification-in-the-united-states-by-generation/ shows that those in Gen x and above (43 year old an above) Republicans have a ~10% margin over Democrats. Even Pew agrees that Party or Leans-Party favors Republicans in the over 50 group by roughly the same margin https://www.pewresearch.org/politics/2020/06/02/the-changing-composition-of-the-electorate-and-partisan-coalitions/