@Monitor(name = "ResponseTimePercentileWhenMillis", type = DataSourceType.COUNTER,
             description = "The time the percentile values were computed in milliseconds since the epoch")
    public long getResponseTimePercentileTimeMillis() {
        return dataDist.getTimestampMillis();
    }
Gets the time when the varios percentile data was last updated,
in milliseconds since the epoch.
ribbon-loadbalancer/src/main/java/com/netflix/loadbalancer/ServerStats.java