public int getMaximum(final String callName) {
		int max = Integer.MIN_VALUE;
		final List<CallData> callDataList = getCallData(callName);
		for (final CallData callDataEntry : callDataList) {
			if (callDataEntry.getDuration() > max) {
				max = callDataEntry.getDuration();
			}
		}
		return max;
	}