My TSP account balance has increased in size by $78,000 from 1/1/2013 - 3/31/13. That is a 12.1% increase for 3 months. Year over Year, my account has increased in value by $120,707 or 19.9%.
My exact number is a mystery. :)
One more note, if I had been all G(T-bills), for the last year, I would be up $8,800 for the year. I think learning how to manage risk is worth the risk.