Welcome to LPSG.
Please have a read through the Unofficial Site FAQs:
http://www.lpsg.org/underwear-clothing-and-appearance-issues/34582-a-completely-unofficial-size-faq.html
In particular, note the following section:
What about racial differences?: When penis size studies first began being issued immediately after WWII statistically significant but small, i.e. half-inch, differences were found between the average erect sizes of men of different races. However, overall body size studies at the same time also showed distinct differences between races that have tended to disappear over time as nutrition around the world has evened out and improved. Some sixty years on, the overall physical averages between races have greatly reduced in variation. (Better nutrition is generally held to be the reason, but better that is, less racially biased experimental methodology may also account for this difference.) Newer studies suggest that if there
ever was a real difference, penis size has now also evened out. Studies are conflicting in this regard, but the older the study the more likely it is to find significant racial differences. Despite the persistence of the rumors, and they pop up here at LPSG repeatedly, there is no evidence that size difference is racial rather than individual.
(A word of advice to newbies: Posting your anecdotal experience about racial differences is rarely well received.)