T1: many many moons ago in college (1979) - 3 mos
T2: 1 yr later - 3 sessions
T3: 2002 thru 2014 every 2 to 4 wks
T4: currently every 7 to 10 days

Maybe your T is starting to think she's not doing you much good anymore? You need to talk about this with her and tell her how you feel. Explain what it is that helps you or doesn't help you.
One of the really cool things my new T keeps saying is that I'm the one in control of what we do in therapy - as far as topics to cover and how often I need or want to see her.