When Joseph Hill Coles was 17, he sold drugs for food, slept in LOVE Park, and withstood the indignities of adult homeless shelters.

One of an unknown number of homeless youths in Philadelphia, he risked injury, emotional torment, and worse, living open and unprotected on the streets of the city.

"Anger consumed me," said the young man, who aged out of foster care. "I was someone no one seemed to want. I was running wild, a complete mess."

Coles, now a 22-year-old youth advocate, shared his story at a hearing Thursday before the joint City Council Committees on Children and Youth, and Housing, Neighborhood Development and the Homeless.

A packed Council chambers gallery of more than 200 people listened to sometimes disturbing testimony from young people as well as from homelessness advocates.

Between 2009 and 2013, the percentage of Philadelphia public school students who had ever experienced homelessness increased, city figures show. In 2013, there were more than 3,600 city high school students who said that they once considered themselves homeless, according to Joe Willard, vice president for policy at the People's Emergency Center, a nonprofit that provides supportive services for families, women, and children.

How many youths are homeless at one time is confusing and a difficult number to discern, experts say. And the terminology itself can be difficult, since some consider youths to be as old as 24, while others say the limit is 18.

The city received $31 million in 2014 in federal funding for the homeless, just $1.1 million of which was provided for youth services, according to Council members Helen Gym and Allan Domb, among the hearing's organizers. They said they wanted to hold the hearing to work toward a plan to address the issue.

A large proportion of homeless youth in Philadelphia are either young people who aged out of foster care, or LGBTQ youth who found themselves rejected by relatives and kicked out of families.

"It's amazing to me the issue of youth homelessness exists," Domb said. "It's terrible to have homelessness; it's worse to have young people homeless."

Liz Hersh, director of the city's Office of Supportive Housing, said the goal is to make homelessness "rare, brief, and nonrecurring." Homeless young people more often experience behavioral problems and are driven to suicide, she said.

Shelters aren't the proper place for young people, Hersh added, saying that they need transitional or permanent housing help.