Id read this before, which is why I only put, Les annees, instead of that and, Les ans. Ans, is used when saying for example, it took me three years to finish, not, it took me years to finish. When you say, the years, its like my last example, a duration example. So, the years, should be only, Les ans, correct?
They talk about it here: http://forum.wordreference.com/showthread.php?t=9547