George Washington University was removed from the nation's premier college rankings list Wednesday after reporting it had inflated numbers surrounding how well last year's freshman class performed in high school.

The university was ranked 51st in the country after giving U.S. News & World Report a value for the percent of the fall 2011 entering class who were in the top 10 percent of their high school class that was 20 percentage points too high.

That figure counts for 6 percent of a school's ranking. At No. 51, George Washington was tied with Boston University and Tulane University. It had slipped one spot, from the No. 50 ranking.

On Wednesday, U.S. News & World Report officials said they had decided to move GW to a category of unranked schools until the 2014 edition of the college guide could be released in September.

University President Steven Knapp assured students the inflated numbers were not intentional, but an accounting misstep.

"I deeply regret this error and want to assure you that corrective action has been taken and safeguards put into place to prevent such errors from occurring in the future," Knapp wrote in a statement posted to the university's website last week, when the error was discovered.