@Monitor(name=PREFIX + "CircuitBreakerTrippedPercentage", type = DataSourceType.INFORMATIONAL)    
    public double getCircuitBreakerTrippedPercentage() {
        ZoneSnapshot snapShot = loadBalancerStats.getZoneSnapshot(zone);
        int totalCount = snapShot.getInstanceCount();
        int circuitTrippedCount = snapShot.getCircuitTrippedCount();
        if (totalCount == 0) {
            if (circuitTrippedCount != 0) {
                return -1;
            } else {
                return 0;
            }
        } else {
            return snapShot.getCircuitTrippedCount() / ((double) totalCount); 
        }
    }
Class that stores Statistics per Zone (where Zone is typically a Amazon
Availability Zone)

@author awang

@param <T>
ribbon-loadbalancer/src/main/java/com/netflix/loadbalancer/ZoneStats.java