The Washington Post puts out it's annual list of “most challenging high schools” -- seven from Houston are in the top 100, and all of them are charter schools.

The index scores the number of college-level tests given during the previous calendar year, divided by the number of graduates.

Houston's Carnegie Vanguard, Energized for STEM and Harmony Science Academy all scored high on the list.

Chuck DeVore at the Texas Public Policy Foundation is not surprised.

“They provide variety, they provide choice, and they provide quality,” DeVore tells KTRH News.

Just 9-percent of 22,000 public schools made the list.

David Dunn at the Texas Charter School Association says that proves a one glove fits all public school system just doesn't apply to some kids.

“Most of the time kids are dropping out not because they're bored with school and can't do school, but because they've got kids of their own to take care of, or they're providing income for their family,” says Dunn.

DeVore believes this is why Texas needs to expand it's charter school program.

“The state legislature in Texas did lift the cap on charter schools, there was over 100,000 kids on the wait list for the schools,” he says.  “But we need to do more, we need to provide more choice, more cooperative educational opportunities for the students of Texas.”