If you want an accurate study you need to go to an area where all crime is classified by the same group on the same standards.
The united states for example. California has the strictest gun control laws and the highest homicide rate and a pretty high gun homicide rate. They also have the dirtiest culture.
Besides all these technical points. If you want to write anither law just make sure it will make a difference not just clog up the airwaves about nothing. Come up with something decent without t
aking away my 2nd ammendment.