Fig. 4

The federal research funds allocated to research and their correlation with the research output. A The federal research funds are expressed as a percentage of gross domestic product per country. B The amount of federal research funds spent per country. C Correlation analysis between the federal research funds and number of publications. D Correlation analysis between the federal research funds and the number of citations. The gross domestic product (GDP) values were extracted from the United Nations Development Program (2019). The countries are classified based on the human development index of the United Nations Development Program (UNDP, http://hdr.undp.org/en/countries). The papers and their respective citations were adjusted per one million individuals to allow comparison between groups. GDP: Gross domestic product, %: percentage, M: Million individuals