Looking only at gun related deaths before and after heavy gun regulations or banning of firearms is only looking at a very skewed one side of a multifaceted issue. For example, when guns are banned, those who would normally commit suicide with guns simply find other ways to off themselves. The statistics show that less deaths occurred because of guns, but the suicide rate does not change.
If we look at the statistics for how many deaths were prevented by guns because responsible citizens were able to counter a gun assault with their own firearm, we get into millions of incidents each year where the bad guys who were stopped by firearms would have been successful.
In other words, regardless of how many deaths occur by gun, we need to look at whether or not many of those deaths are being prevented at all (in the case of suicides) and what the ratio of good guys being killed versus bad guys being killed is. When responsible citizens no longer are able to fight fire(arm) with fire(arm), a higher percentage of the deaths by firearms becomes victims of criminal activity rather than the criminals themselves.
I will willing give up my firearms the day that an armed police officer can be assigned to each and every citizen. Until that day comes, every citizen should have the right to be able to protect themselves against the bad guys, with equal or better abilities.