I found this article titled Births of Twins up Dramatically since 1980 on CNN's health section. The author of the article was Jacque Wilson, CNN.com's Senior Associate Producer and it was posted January 5th, 2012. Here is the link to the article:
1. The survey was conducted by Joyce Martin, Brady Hamilton, and Michelle Osterman.
2. The sponsor for the research was undisclosed.
3. The sponsor could be interested in the reasoning for the birth of twins as opposed to one child. The study showed that older women had an impact on the amount of twins. The study said it was responsible for approximately one third of the increase.
4. Information on methodology is included which indicates that much of the data was attained from the Natality Data File from the National Vital Statistics System.
5. Yes, there are several well labelled sections.
6. Yes, there are several histograms and charts with clear and descriptive titles.