Both. And neither. Sometimes IzzyMouse would take me totally by surprise by eating 3 times the quantity she would normally get through (sometimes a little embarrassing if I'd already eaten some of her share, wrongly anticipating how much she'd want...) but she wouldn't necessarily repeat that every day. So I'd see sporadic jumps, but then over time I could also see the underlying trend going up. Does that make sense? I'm not sure economic analogies are really working here...