Here's the deal...

After 3500 hands of 25nl full ring my average profit is 5bigbets/100hands. So $2.50 every 100 hands at 25nl isn't bad but... my HEM graph shows my non-showdown winnings declining quite a bit and I feel like I'm losing out on a lot of money when I look at it. Unfortunately I'm at work and don't have access to the graph to show, but I'm curious if this is normal or if there is something I need to be doing to stabilize this.