I don't feel that fluency means anything that can be defined in such a manner that talking about it in numbers is *ever* realistic. This is a view I've formed running renshuu for 20 years as well as being a language teacher for almost 15.
As several people have noticed, fluency itself is almost impossible to define, as it means different things to different people. I think these "it takes this many hours to reach this level" charts are almost entirely useless.
Even for something as relatively "simple" as passing the N5, you have a HUGE range of things that could be defined as such. (putting aside the fact that passing the JLPT is hardly correlated with fluency for most people because it does not test any form of production.) There is a roughly 20-30% range in accuracy that defines "passing". On top of that, because it's a test without any written form, there are ways of answering some questions by "beating" the test, not by actually having mastery over the materials. (strategies for eliminating multiple choice answers, etc.).
Then, there is an often overlooked but critical element of fluency = speed of thought and processing. One can "know" any amount of language, but if it can not be processed or produced in a certain amount of time (and this time changes depending on the form of the language: spoken, written, internet, etc.), then the value of that knowledge is greatly reduced.
Additionally, an "hour" doesn't really mean much because we cannot really define it well across people or groups of people. An hour of "studying" depends on the following things (among 1,000 other things)
1. Stress levels
2. Motivation
3. Environment (visual, temperature, noise, etc.)
4. Sleep levels
5. General health
6. What you did just before it, what you have to do next
7. Emotions
8. How much of this "studying" took place earlier in the day, week, month
9. Studying style
10. Distractions
Just to name a few.
We can ignore fluency, and choose an easier topic: "learning" the hiragana alphabet. I see some people on renshuu who feel they've mastered it in 2 days, and others who take months. That's the amount of range created by those factors above.
This post might sound somewhat gloomy, but it's not. What I hope to convey is that I feel those numbers given out by people and website are more dangerous than not, because they can make you think that you're a failure because you don't match up to what others say is "normal". There *is no* normal.
So I tend to suggest that only you have the current set of variables in your life that are going to control how your learning progresses, so there is only one person you can really compare yourself to.
