This book review points out that the data in CIA World Factbook is metric. http://www.huntingtonnews.net/columns/091107-kinchen-columnsbookreview.html NOTE: I would point out the Factbook is available, free, online here: https://www.cia.gov/library/publications/the-world-factbook/index.html After reviewing a few countries, the data is mostly metric with a few exceptions and examples of bad usage: *Maritime claims are in nautical miles, abbreviated "nm." Our 200 nanometer coastal waters might be hard for the Navy to defend. No issue with the nautical miles but they shouldn't reuse a valid SI symbol, use M, NM, nmi, etc *Prefixes: Rather than change prefixes, they add a "large number word" eg 4.11 trillion kWh (these are defined in Appendix G, using US definitions) *Oil: In barrels of 42 US gallons (but natural gas in cubic meters) They don't use any superscripts or special characters, so areas and volumes use sq and cu preceding a length unit. Appendix G (Weights & Measures) repeats the myth that only the US, Liberia, and Myanmar are non-metric. As spies, they should know the truth. But it is not a bad collection of conversions. Where there is an issue, units are US unless marked as British.
