Dave Kopel on expansion of "shall issue" CCW
It's posted at the Volokh Conspiracy, which is now one of the Washington Post blogs (a wonder in itself!)
Basically, in 1986:
Under 10% of the US population lived in "shall issue" States.
About 33% lived in States that had no CCW permit process at all.
The remaining 57% lived in "may issue" States.
Only residents of Vermont could carry concealed without a permit.
As of today:
66% of the population lives in "shall issue" States.
No States have no CCW permit system at all.
27% live in "may issue" States.
7% live in States where you can carry concealed without a permit.
(And if the effect of the Peruta ruling is to make "shall issue" the rule in California and Hawaii, the percent in "may issue" will fall to 14%, and "shall issue" will rise to 79%).