Jason,
I realize you are a very buisy guy right now with all the college/graduation stuff going on (i feel your pain), and i hadnt noticed this untill just now. I've finally come to the point were i've been adding to the database for over a year. Is there a way ( i realize this should require much work, but perhaps get the people to input a year?) so taht the graph will show a different curve for different years?

 

I've been asked this a few times. Basically, when I first made the database I didn't think to add this feature, and if I were to add it now, there really isn't a way to distinguish between one year and another automatically without the member having to update their tanks. Many people haven't updated in a while, though.