There could be a data quality issue in the "Youth Turnout rates by age and election year" chart. Notice the curve appears to have a similar trend and pattern, which raises an eyebrow as the data source is not in a published website. However, when educator engages students on this task, they should take notice of this and possibly not use the chart. They can get this kind of chart from the EPA, New York Times, or other credible published sources. Aside from this shortcoming, this resource is recommended for teaching.