Baystock, the chart link that you provided has nothing to do with the general point you are trying to make in your post.
This gold/oil chart was generated simply for investors/traders to try and create some correlation between gold (silver) prices versus oil prices. This was especially popular since the 1970's due to turbulence in oil prices during that decade (see link below).
The fact that the current ratio is in the 20's (currently 24), is not a good thing, actually it's a bad thing. As you will see from the original article and chart provided in the link below, a ratio above 21 indicates that Gold is overvalued and Oil is undervalued. Anyway, the real importance as to where Gold is going has everything to do with Gold demand vs supply, and nothing more. The Gold/Oil ratio is a nice piece of information to know for historical purposes but that's all. The chart will not tell you anything other than past historical ratio of Gold vs Oil.
Now, your point about fuel costs being lower and therefore benefiting users of energy is obviously correct and a logical argument but the chart you attached has nothing to do with this argument. The actual amount of fuel savings to Banro is yet to be determined and I'm sure they will mention something about it in the next quarterly financial report.