Harvard, the world's richest university, said Thursday a record 22,955 students applied for a spot in the Class of 2011. Of those, just 2,058 were accepted -- an admission rate of 9 percent, the lowest in school history.

Last year, 2,109 of 22,753 applicants, or 9.3 percent, got the nod from the university in Cambridge, Massachusetts, near Boston.

Harvard and other prestigious U.S. universities are benefiting from a surge in enrollment as children of the baby-boomer generation graduate from high school.

Harvard, whose former president Lawrence Summers was criticized for controversial remarks about women, said just over half of those admitted to the Class of 2011 were women, while the number of ethnic minorities hit a record high.

Nearly 20 percent of those accepted are Asian, 10.7 percent are black and 10.1 percent are Latino. The class would also be its most economically diverse, Harvard said, with 26 percent eligible for a new financial aid program.

The Harvard Financial Aid Initiative, announced in 2004 by Summers, slashed the amount low-income students must pay to attend the oldest U.S. institute of higher learning.

Under the program, students from families earning less than $60,000 a year do not have to contribute to the cost of tuition. Those from families earning between $60,000 and $80,000 pay far less than they would have in previous years.

Since the program began, aid for students from families with incomes under $60,000 has risen 34 percent, Harvard said.

More than two-thirds of Harvard's entering class receives financial aid, including scholarships and loans, while more than half qualify for scholarship assistance and an average total aid package of close to $34,000.

Many badly need the help. Annual undergraduate tuition will rise 3.9 percent next year to $31,456, increasing at a pace nearly double the U.S. rate of inflation, a Harvard statement showed this month.

Throw in room, board and services fees and the cost jumps to $45,620, almost double the average at a private college in the United States.

Summers, a former U.S. Treasury secretary whose confrontational style led to a faculty vote of no confidence, resigned last year. Historian Drew Gilpin Faust, Harvard's first female president, has been appointed to replace him.