public double getMinValue() {
		if(times.length == 0) {
			return -1;
		}
		double minval = times[0];
		for(int i = 1; i < times.length; i++) {
			if(times[i] < minval) {
				minval = times[i];
			}
		}
		return minval;
		//returns minimum value of times-array
	}