That stat is off by a couple orders of magnitude. The total number of death penalty convictions overturned by DNA evidence is 29 (as of 2025). There are a couple thousand death row inmates right now, and the denominator here is all the people who were on death row in the last 20+ years. That's a rate of significantly <1%.
https://deathpenaltyinfo.org/first-death-row-exoneration-inv...