1. Peter Corbett did the statistics and the analysis that went with it. He performed these statistics two years ago and compared the results.
2. It seems like he sponsored / was able to find the selected data.
3. He was curious in finding out the result to inform the general population who uses Facebook that the older generation does have a big impact on the total population of Facebook.
4. His sample size was dependent on the number of users that use Facebook and the number of users in the demographic of 35-54 years old.
5. Yes, he gives percentages for users within certain age groups, location in the United States and gender.
6. No, no graphs were used in this article but a table was, and that was clearly given.