For the first time in US history, the high school graduation rate has risen above 80 percent. ABC News reports 81 percent of America's high school students are graduating - and that may be a milestone. But there are decidedly mixed results in this report, using numbers from the US Department of Education. For low income students, the graduation rate is just 72 percent. In big cities, the average is in the 60s. There are significant racial disparities. And while the overall graduation rate may have gone up 8 points in just the last six years - one out of every five students is still leaving high school without a diploma.