Official figures found the increase in crime was even higher in London, at 18%.
The cause of the rise has been disputed. Police have said the increasing availability of blades on the internet, and a lack of checks on who's buying them, is behind the increase.
Others have said a relaxation in police stop and searches has caused the rise.
XLP works with young people in inner-city London and beyond, some of whom are or were in gangs. It's CEO, Patrick Regan OBE, has said a young person's fear of violence from other people, and a fear that they cannot achieve anything meaningful in their lives, is the main reason behind why people carry knives.
Mr Regan said unless this culture of fear changed, knife crime would always be a problem.
He told Premier's News Hour: "We have to create positive alternatives for our young people, and change the 'I've got nothing to lose' mentality so they feel like they've got a real stake in their lives and in what's going on.
"Young people have huge potential but there is a sense that that potential could be overwhelmed by a sense of fear, because fear is the main why a young person would carry a knife. I've often said to young people you can't protect yourself with a knife, it's an offensive weapon, but they say to me: 'if people know I've got a knife on me, they're not going to pick on me'.
"We run a mentoring programme here and we support parents through that and a lot of the parents say to us 'thank God we don't have to do this on our own anymore'. Getting other support in the kid's lives, role models that they can aspire to be like, people who are positive and are going to help them."
Listen to Premier's Marcus Jones speaking to Patrick Regan OBE on the News Hour:
