I just got the 2009 AT&T phone book. Every year I like to go through and see which investigators that was in there last year, are gone. I have so far only did part of my analysis. Here is what I got so far.
12 investigative agencies that was in the 2008 AT&T phone book, are not in the 2009 book under the heading of Investigators.
That's 12 out of 53. More than 20% have presumably gone out of business.
My next step is to see how many investigative agencies sprung up this last year. I will let you know what I find.