Hospitals saw a slight fall in the number of people needing treatment after being injured in violent attacks, academics have revealed.
There have been decreases every year except for 2008 which saw a 7% rise.
Those most at risk were males aged 18 to 30 and emergency room attendance peaked at the weekend and in March, May and August.
Figures revealed an 8% increase in the number of cases of children aged up to 10 being treated after violence.
Professor Jonathan Shepherd, from the University of Cardiff, said it was not clear what was behind the rise.
He said: “The question is why and we don’t really know why.
“One explanation that has been put forward is it is more difficult for children to be taken into care by local authorities and that may mean more young children are staying in risky home situations than they were before but that is just a proposal.”
Cardiff University academics collected data from 44 A&E departments and walk-in centres in England and Wales.
Among the hospitals taking part in the survey were Blackburn Royal Infirmary, Hillingdon Hospital in London, Stoke Mandeville Hospital in Aylesbury and the University Hospital of Wales in Cardiff.