A change in the protocol of emergency response personnel is also credited as contributing to the high survival rate in the region. Guidelines set by the American Heart Association in 2000, recommend repeated shocks from a defibrillator and to check for a pulse prior to starting CPR. Medic One guidelines, established in 2005, are to provide a single shock from a defibrillator followed immediately by two minutes of CPR, beginning with chest compressions. This has dropped the average time between first shock to starting CPR from twenty-eight seconds to seven seconds, resulting in a near 50% increase in the previous rate of survival. For every one hundred cardiac arrest calls, now an additional thirteen patients will live.