No Lawyers - Only Guns and Money reader Rob Vance did even better.
He's got a graph of it over time from 1985 to the present. The conclusions are great too.
Here's a taste:
1) In the early 1980s 90% of Americans lived in states that actively suppressed self-defense rights by severely limiting concealed carry of firearms by citizens.
2) By 2010, 2/3’s of Americans lived in states where law abiding citizens could conceal carry if they met minimal standards, and in some states (4 by 2011) needed NO state permission at all to concealed carry. A total of 41 states are now shall-issue or have unrestricted concealed carry status.
3) Few states moved from no issue to may issue. Rather when states made policy changes, they made the jump from no-issue to shall-issue all at once (again, with a couple of exceptions).