function getYears(array) {
	var oldest = Infinity;
	var youngest = 0;

	while (array.length >= 1) {
		var last = array.pop();

		if (last < oldest) {
			oldest = last;
		}

		if (last > youngest) {
			youngest = last;
		}
	}

	var tmp = new Date();

	console.log(oldest, tmp.getFullYear() - oldest, 'oldest');
	console.log(youngest, tmp.getFullYear() - youngest, 'youngest');
}


getYears([1991, 1654, 123, 1999]);