| Panel A: The top 10 most productive countries in the period 1936–2020 | Country | A | TC | TC/A | NC | Main collaborators |
| United States | 134 | 2,249 | 16.78 | 14 | Canada, United Kingdom, Australia | United Kingdom | 75 | 1,407 | 18.76 | 13 | United States, Canada, Australia | Australia | 33 | 406 | 12.30 | 5 | United States, United Kingdom, Brazil | Canada | 21 | 170 | 8.10 | 5 | United States, United Kingdom, France | Brazil | 16 | 51 | 3.19 | 3 | Australia, Ecuador, Portugal | Ireland | 13 | 128 | 9.85 | 2 | United Kingdom, Brunei | China | 12 | 49 | 4.08 | 1 | Canada | Germany | 7 | 24 | 3.42 | 3 | United Kingdom, Switzerland, Vietnam | Italy | 7 | 221 | 31.57 | 2 | United Kingdom, Finland | France | 6 | 42 | 7.00 | 1 | Canada |
| Panel B: The top 5 most productive countries in the period 1936–2004 | Country | A | TC | TC/A | NC | Main collaborators |
| United States | 74 | 1878 | 25.39 | 5 | United Kingdom, Canada, Belgium | United Kingdom | 26 | 819 | 31.50 | 4 | United States, Ireland, Brunei | Australia | 16 | 238 | 14.88 | 0 | | Canada | 6 | 43 | 7.17 | 1 | United States | Ireland | 4 | 30 | 7.50 | 2 | United Kingdom, Brunei |
| Panel C: The top 5 most productive countries in the period 2005–2020 | Country | A | TC | TC/A | NC | Main collaborators |
| United States | 60 | 371 | 6.18 | 11 | Canada, United Kingdom, Australia | United Kingdom | 49 | 588 | 12.00 | 11 | United States, Canada, Australia | Australia | 17 | 168 | 9.88 | 5 | United Kingdom, United States, Brazil | Brazil | 16 | 51 | 3.19 | 3 | Australia, Ecuador, Portugal | Canada | 15 | 127 | 8.47 | 5 | France, United States, United Kingdom |
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