"Raw Numbers: Charter Students Are Graduating From College at Three to Five Times the National Average"
There are some measurement problems, but the KIPP system, probably the largest charter system reporting, and the only network that tracks students from the 9th grade instead of just from the 12th grade, has a rate about 2.5 times the national average. And while such a number doesn't reflect the selection of students into charters--put another way, we'd like to have a comparable control sample--it could well be a quite encouraging sign.
Link via my older daughter.
Related: "Charter Schools Help District Schools".