So you're reading it as a "prerequisite chart"? That seems odd because the common way to read graphs is that what's reported on the y-axis is a function of the values of the x-axis.
I find it also hard to read it that way when I look at that "Price in February -> Price in April" annotation: if those two points on the y-axis mark points in time, then so do the correlating points on the x-axis. I can only read that as "from February to April, the demand went up while the prices went down".
I find it also hard to read it that way when I look at that "Price in February -> Price in April" annotation: if those two points on the y-axis mark points in time, then so do the correlating points on the x-axis. I can only read that as "from February to April, the demand went up while the prices went down".