.. Maybe your comprehension skills are poor like so many others here ..
This was unnecessary. Please avoid using ad hominems in the future. Insults towards fellow members and informal fallacies are not welcome here. (I'm kidding about the informal fallacy part... a bit

)
He said most stop between 17 and 21 and wikipedia said most stop between 16 and 17 ... there was nothing added by you saying but thats the average ...
What he was trying to say is that wikipedia only lists the average age at which puberty ends, which sits between 16 and 17, give or take. This does not represent the entire range of possible ages at which puberty ends in males.
The normal variation in the age at which adolescent changes occur is so wide that puberty cannot be considered to be pathologically delayed until the menarche has failed to occur by the age of 18 or testicular development by the age of 20.
- Excerpt from Wikipedia:
Delayed puberty - Wikipedia, the free encyclopedia
If you read through the above link, you will see that puberty has a very wide range. The average that is listed on the page you looked at (ages 16-17) is the mode, based off of the frequency of puberty's end in children; however, since the range is quite wide, this average does not readily demonstrate every common end to puberty. As my quote says above, final reproductive development is not considered 'Delayed Puberty' until the age of 20, a number that has been frequently referenced on this forum as the final finish line for puberty.
Given the above material, I'd say it is fair to assume that you may not be done puberty yet if you are below the age of 20, but the majority of individuals your age are, in fact, done.
Your length is fine, and your girth is a bit on the thin side compared to the averages. This does not mean you are too small, since 'too small' is relative to the desires and preferences of the woman you are involved with. PE is a personal venture. It can improve your sex life for you and your partner, but it is not really that important at the end of the day. Don't worry about whether your penis is too small or not. Instead, ask yourself if you would like to have one bigger, regardless of how much your woman enjoys it. If the answer is yes, then enjoy your stay and get jelqing
Just remember, comparing sizes will only hurt you. There are always bigger fish. If you PE, do it to reach your own goals, not another woman's, or society's, or anyone else's.