And how carbon heavy the rest is, like gas vs. ignite.

I think the major problem with the chart is the fact the the chronological development cannot properly be read. There is a connection between the dots that suggests the temporal connection. But the direction is mostly unclear.

Also why did you choose to plot these two variables against each other. The strong negative correlation is expected. There are exemptions, but it's hard to tell when they occurred for a country. And then, is this interesting at all?