How are we going to set about "measuring" safety? By the number of reported electrocutions and electric-related fires? The statistics for the former are probably quite reliable, but for fires it's been mentioned here before that statistics are somewhat dubious, in view of different approaches in various juridictions and the tendency to blame as electrical any fire whose cause cannot otherwise be determined.
C-H has certainly hit the nail squarely on the head as far as many Brits are concerned. I'd say that the majority of people in the U.K. class the British system as "the best in the world," although personally I would challenge that.
Another point is whether we're going to examine the safety angle from a fully code-compliant installation in each country, or whether we're going to take a typical
system, which is often quite different.