Feel free to look at the numbers in the PRIA [1]. Those 360 deaths are a significant reduction in fatalities from baseline in the types of collisions they expect to be impacted by this rulemaking. That baseline itself assumes some 65% of new vehicles will come with compliant AEB systems regardless of this rulemaking.

[1] https://www.regulations.gov/document/NHTSA-2023-0021-0004