Actually:

According to the latest annual statistics for crime in England & Wales:

A British Crime Survey reported that out of the 2,715,000 violent crimes reported; those involving use of weapons make up almost 75% of the incidents with a sharp implement making up about 27% of the reported crimes.

Overall statistics indicate that homicides have more than tripled from 1965 to today.

Around 10% of 11-12 year olds reported carrying knives last year alone and 46% of 15-17 year olds admitting to carrying knives for self defence out of neccesity.

According to Ian Johnston the Chief Constable for British Transport Police & the Justice Board / Mori in 2003:

"Pupils in London Schools carry knives on average 30-35% of the time and that 1 in 5 of 16 year old boys admit to having attacking someone with a knife with the intent of causing serious injury."