Around 10% (*edit*) in 2022 14% in general, 16,1% in Copenhagen Area (sorry, in Danish only): out of hospital cardiac arrest:
https://hjertestopregister.dk/wp-content/uploads/2023/06/Aarsrapport-fra-Dansk-Hjertestopregister-2022.pdf
Have been implementing these, first in Greater Copenhagen, now in hole country
https://heartrunner.com/