The number of high school seniors who entered high school in the ninth grade and graduated in four years is down a little from 2012 and 2013.

americashealthrankings.org

In 2012 and 2013 the percentage of incoming 9th graders who graduated in four years with a regular diploma was around 84 percent.  In 2014, those numbers are closer to 79 percent.  

Now, this study at americashealthrankings.org doesn't take into consideration those students who might have chosen an alternative means of graduation, or super-seniors, who took longer than 4 years to graduate. So, keep in mind that the story here is a little incomplete.

americashealthrankings.org

I also found that you have to be really careful when interpreting stats. Take a look at the chart above and you might do a double-take. As you look at things that positively affect graduation rates, you might draw the conclusion that if we only had more smokers and violent crimes, we'd be passing out more diplomas. That's simply not the case. Idaho fares well in these areas because overall, this is where Idaho does well. (Idaho's comparatively low violent crime rates have a positive effect on graduation numbers.)