I thought it was 5 years, but it looks like it's been a bit longer now..

First T: Fall 2004-Summer 2006
Crazy T: Fall 2006
No T: Winter 2006
Crying T: Spring 2007
First T: Summer 2007
Best T: Fall 2007 - Summer 2009
Bad T: Fall 2009
New T: Winter 2009 - Present

So I've had 6 that I've worked with for more than an interview, but only 3 that I can clearly define as progressive chapters of my life, all female. I've also had 4 pdocs, all of which have been male.