Bachelor Thesis – How Do I Find Data?

Dear fellow redditors,

for my thesis, I currently plan on conducting a data analysis on global energy prices development over the course of 30 years. However, my own research has led to the conclusion that it is not as easy as hoped to find data sets on this without having to pay thousands of dollars to research companies. Can anyone of you help me with my problem and e.g. point to data sets I might have missed out on?

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