When we considered the number of retirements surrounding redistricting elections, our snap judgment was there were greater number of incumbents who bowed out in redistricting years rather than in a normal election cycle. After a review of he election from 1970 until 2020 the answer is correct.
In the Senate, incumbents average 12.12 retirements in redistricting elections compared to 9.64 in regular elections. In the House, the numbers are double 32 retirements in redistricting years and 16 in regular election years on average. Now, the House figure is skewed because House members frequently run for the Senate, an average of 4.2 members in redistricting elections and 4.9 on average are elected in regular election years.
Coincidentally, all of the election we reviewed, the redistricting plans were all decided by a court, rather than the state legislature.
We have included a spread sheet for you to review the elections.