var percentile(vars data, int length, var percent)
{
	int* ids = sortIdx(data, length);
	var pos = (length-1)*percent/100;
	var below = data[ids[min(length-1, (int)pos)]];
	if(pos == round(pos))
		return below;
	var above = data[ids[min(length-1, (int)pos+1)]];
	return (below+above)/2;
}