Please add total pollution produced and removed

[ejg]

The pollution statistics are nice but if would be nice if the stats would stack or something.

Please add total pollution produced and removed to the graph. Either as a separate quantity but maybe by stacking the graphs.

Stacked graphs so that you can see what part of pollution is caused by what (visually). Also, by doing this both in pollution produced and pollution removed you can see which one is larger: removed or produced. Then you know if your pollution in the world is diminishing or is growing.