The physician-led pre-hospital service London HEMS examined its penetrating trauma caseload between 1991 and 2006. Overall, stabbings rose annually by 23.2% and shootings by 11.0%.
Is the prevalence of deliberate penetrating trauma increasing in London? Experiences of an urban pre-hospital trauma service
Injury. 2009 May;40(5):560-3
http://www.ncbi.nlm.nih.gov/pubmed/19232594