We have observed from the graph that there is a revenue line for ground rent line graph. Oil Companies do not generate ground rent. For this reason we suggest that you separate Oil companies from mining companies and use their corresponding revenue stream to plot the graphs. Separate the graph: Company contribution by revenue stream into Mining graph and Oil and gas graph because they are of different currency unit. (Mining is in Ghana Cedis and Oil and Gas is in dollar)
This comment doesn't make sense to me:
Company contribution by revenue stream