I'm working in a paper (https://www.researchgate.net/publication/264418342_Capital_Stock_in_Machinery__Equipment_and_Energy_Consumption_Patterns_between_Latin_America_and_Western_Europe._1800_-_1970) with several times series and I want to save some space. 

I have done this graph

Energy Capital ratio 

Europe and Latin America 1870 -1970

​

The problem, i that I need to put en any little graph another variable (Energy Intensity in this case), something similar to this simple plot

​

Do you have some ideas or I must do it with R? 

I'm a really Gretl fan so i preffer to do with this great software!

Thank you everyone for this user list 

--