Guns...

I'm afraid I can only find Wikipedia's page again, where statistics are primarily drawn from WHO and UN.  Countries that match the list above are shown below:

Australia 0.09

Austria 0.18

Canada 0.5

Czech Republic 0.12

Finland 0.26

France 0.22

Germany 0.06

Hungary 0.13

Iceland Italy 0.36

Japan 0.02

Luxembourg 0.6

Netherlands 0.2

New Zealand 0.17

Norway 0.04

Portugal 0.48

Slovakia 0.18

Spain 0.15

Sweden 0.19

England and Wales 0.04

Northern Ireland 0.04

Scotland 0.04

United States 3.7

These are in homicides (not all deaths) per 100,000 population.

Average across all non-US countries is 0.194 deaths per 100,000, compared to 3.7 US.  Which suggests a multiple of about 19.