STEVE EMBER: Sixty percent of current Peace Corps volunteers are women. The average age of a volunteer is twenty-eight. But the ages of Peace Corps volunteers range from eighteen to eighty-six. Some Americans join the Peace Corps after they retire.

Today seven percent of volunteers are over the age of fifty. And nineteen percent are members of minority groups.

This year's budget for the agency is four hundred million dollars.

FAITH LAPIDUS: Allegra Troiano is based in Costa Rica as a regional adviser for the Teaching English as a Foreign Language program of the Peace Corps. She says the way Peace Corps volunteers teach English has changed.

In the past, volunteers were placed in a classroom to teach English by themselves. But now, Ms. Troiano says the aim is to work with local teachers to provide what is known as co-teaching.

ALLEGRA TROIANO: "In teaching English as a second language, the goal is to put Peace Corps volunteers in classes with host country national teachers. So they have established that this model of co-teaching is the most sustainable."

She says the Peace Corps is currently expanding programs in countries like Costa Rica to meet growing demand for English teaching.

ALLEGRA TROIANO: "It’s the way to communicate with the global world. So I think there's a great need and I think there's also a great desire."

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STEVE EMBER: One former volunteer is Aaron Williams. He is now the director of the Peace Corps.