When it comes to graphs simplicity is the key. This is often why people use bar graphs or pie charts.These forms of graphs are the most efficient when it comes to allowing the reader to understand the statistics being given. Between the two graphs depicted. Most would prefer the bar graph because it shows a very simplistic comparison between the two data measures. It's also obvious to to see the benchmarks that each category approaches . Also the bar graph separates the categories by color to differentiate between adult and child.
The second graph depicted is a line graph.This is another popular form of graph used. It shows the gradual increase of data over time intervals. I prefer bar graphs to these because the can be a little bit more confusing and force the reader to concentrate more. The bar graph depicted also did a good job of putting actual values at the end of bars. This allowed the reader to be more exact while easily understanding the graph at the same time.