CPR can double or triple a persons chance of survival after cardiac arrest

CPR, especially if administered immediately after cardiac arrest, can double or triple a person’s chance of survival. Unfortunately, about 90 percent of people who experience out-of-hospital cardiac arrest die.

source: https://cpr.heart.org/AHAECC/CPRAndECC/AboutCPRECC/CPRFactsAndStats/UCM_475748_CPR-Facts-and-Stats.jsp